Semiconductor device

ABSTRACT

A semiconductor device can define a plurality of points on the basis of an In ion concentration, a first dopant concentration, and a second dopant concentration, and identify each layer on the basis of a region between the points defined as above. The Mg concentration in a specific layer may increase along a specific direction and then decrease.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a U.S. National Stage Application under 35 U.S.C. §371 of PCT Application No. PCT/KR2018/016619, filed Dec. 26, 2018, whichclaims priority to Korean Patent Application No. 10-2017-0181125, filedDec. 27, 2017, whose entire disclosures are hereby incorporated byreference.

TECHNICAL FIELD

An embodiment relates to a semiconductor device.

BACKGROUND ART

A semiconductor device containing a compound such as GaN, AlGaN, etc.may have many advantages such as a wide and easily adjustable band gapenergy and thus may be used as a light-emitting device, alight-receiving device, and various diodes.

In particular, a light-emitting device such as a light-emitting diode,or a laser diode using a group III-V compound semiconductor or a groupII-VI compound semiconductor may render various colors such as red,green, blue, and ultraviolet light due to development of a thin-filmgrowth technology and new device materials. The light-emitting devicemay realize an efficient white light beam using a fluorescent materialor by combining colors. The light-emitting device may have advantages oflow power consumption, semi-permanent lifespan, fast response speed,safety, and environment friendliness, compared to conventionallight-sources such as fluorescent and incandescent lamps.

For example, a nitride semiconductor for the light-emitting device has ahigh thermal stability and a wide bandgap energy, and thus is in thespotlight for developing an optical device and a high-power electronicdevice. In particular, a blue light-emitting device, a greenlight-emitting device, an ultraviolet (UV) light-emitting device, and ared light-emitting device using the nitride semiconductor arecommercially available and widely used.

Recently, as a demand for a high-efficiency LED has increased, luminousintensity improvement has been a challenge. However, satisfactoryimprovement in the luminous intensity has not yet been achieved.

SUMMARY

An embodiment provides a semiconductor device and a semiconductor devicepackage in which luminous intensity may be increased.

An embodiment provides a semiconductor device that does not require anadditional component to increase the luminous intensity, and asemiconductor device package including the same.

An embodiment provides a semiconductor device in which a recess such asa V-pit contributing to increase in the luminous intensity may beidentified based on change in a concentration of a dopant includedtherein, and a semiconductor device package including the same.

A semiconductor device in accordance with an embodiment includes a firstconductive-type semiconductor layer; a second conductive-typesemiconductor layer on the first conductive-type semiconductor layer;and an active layer disposed between the first conductive-typesemiconductor layer and the second conductive-type semiconductor layer.

When primary ions are irradiated to the first conductive-typesemiconductor layer, the active layer, and the second conductive-typesemiconductor layer, secondary ions are emitted from the firstconductive-type semiconductor layer, the active layer, and the secondconductive-type semiconductor layer. An indium (In) ion intensity, asilicon (Si) concentration, and a carbon (C) concentration of the firstconductive-type semiconductor layer, the active layer, and the secondconductive-type semiconductor layer are detected based on the emittedsecondary ions.

The semiconductor device has a plurality of inflection points of theindium (In) ion intensity, wherein the indium (In) ion intensities atthe plurality of inflection points are 0.3 to 0.5 times of a highestindium (In) ion intensity in a vertical entire region of thesemiconductor device, wherein the semiconductor device has: a firstpoint having the same indium (In) ion intensity as a lowest indium (In)ion intensity among the indium (In) ion intensities at the plurality ofinflection points, wherein the first point is adjacent to a locationhaving a lowest indium (In) ion intensity in a direction toward a firstvertical end of the semiconductor device; a second point having the sameindium (In) ion intensity as a lowest indium (In) ion intensity amongthe indium (In) ion intensities at the plurality of inflection points,wherein the second point is closest to a location having a lowest indium(In) ion intensity in a direction toward a second vertical end of thesemiconductor device, wherein the first and second vertical ends areopposite to each other; a third point present in a partial region wherethe Si concentration is 0.1 to 0.2 times of a highest Si concentrationin the vertical entire region of the semiconductor device, wherein thethird point has a highest Si concentration in the partial region,wherein the third point is adjacent to a location having a highest Siconcentration in a direction toward the second vertical end of thesemiconductor device; a first inflection point of the Mg concentrationlocated at the same point as the first point; a second inflection pointadjacent to the first inflection point in a direction toward the firstvertical end of the semiconductor device, wherein the second inflectionpoint has the Mg concentration higher than the Mg concentration of thefirst inflection point; and a third inflection point adjacent to thesecond inflection point in a direction toward the first vertical end ofthe semiconductor device, wherein the third inflection point has the Mgconcentration higher than the Mg concentration of the first inflectionpoint, and lower than the Mg concentration of the second inflectionpoint.

The active layer corresponds to a region between the first point and thesecond point, wherein the first conductive-type semiconductor layercorresponds to a region between the second point and the third point.

The second conductive-type semiconductor layer includes a firstsecond-conductive-type semiconductor layer and a secondsecond-conductive-type semiconductor layer, wherein the firstsecond-conductive-type semiconductor layer corresponds to a regionbetween the first point and the second inflection point, and the secondsecond-conductive-type semiconductor layer corresponds to a regionbetween the second inflection point and the third inflection point.

The Mg concentration in the first second-conductive-type semiconductorlayer increases in a direction toward the first vertical end of thesemiconductor device, wherein the Mg concentration in the secondsecond-conductive-type semiconductor layer decreases in a directiontoward the first vertical end of the semiconductor device.

Advantageous Effects

According to the embodiment, each layer of the semiconductor device maybe easily identified based on the concentration of the second dopantand/or the indium (In) ion intensity as obtained from the SIMS data.

According to the embodiment, the shape of the recess may be easilyidentified by tracking the concentration of the second dopant based onthe concentration of the second dopant and/or the indium (In) ionintensity as obtained from the SIMS data.

According to the embodiment, the process may be easily controlled toobtain a desired recess shape or an optimal recess shape by tracking theconcentration of the second dopant based on the concentration of thesecond dopant and/or the indium (In) ion intensity as obtained from SIMSdata.

According to the embodiment, by adjusting at least one of thetemperature, the thickness, and the indium (In) content may allow arecess such as a V-pit extending to the active layer and the p-typesemiconductor layer to be formed. Further, a size of the recess and anarrangement density of the recesses may be precisely adjusted such thatlight from the active layer may be easily extracted through an inclinedface of the recess, and a hole of the p-type semiconductor layer may beeasily injected into the active layer through the recess, resulting inimproved light efficiency. The luminous intensity may be increased dueto the improvement of light extraction efficiency, and light efficiency.

According to the embodiment, the shape of the recess formed in theactive layer may be easily identified based on the change in themagnesium concentration using an ion analysis device.

According to the embodiment, a process of identifying the change in themagnesium concentration in the active layer using the ion analysisdevice may continue. Thus, based on the identification result, therecess shape may be controlled so that a point at which the magnesiumconcentration is at the lowest, that is, a last point where themagnesium concentration is zero is present in the active layer. Thus,the light extraction from the active layer may be maximized whilemaximizing the deep-hole injection effect, thereby improving the lightefficiency and improving the light output and the operation voltage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a semiconductor device according to a first embodiment.

FIG. 2 shows a third semiconductor layer in detail.

FIG. 3 shows a fifth semiconductor layer in detail.

FIG. 4 shows luminous intensity based on an aluminum Al content of thefifth semiconductor layer.

FIG. 5 shows a deep hole injection in a semiconductor device accordingto an embodiment.

FIG. 6 shows a second carrier profile when each of the thirdsemiconductor layer, a fourth semiconductor layer, an active layer andthe fifth semiconductor layer is free of a recess.

FIG. 7 shows a second carrier profile when each layer has a recess.

FIG. 8 shows a second carrier profile when a density of recesses isexcessive.

FIGS. 9A and 9B show a gradient of a magnesium concentration based on asize of a topmost region of the recess in the active layer.

FIGS. 10A and 10B show a gradient of a magnesium concentration based ona depth of the recess in the active layer.

FIG. 11 shows a horizontal semiconductor device.

FIG. 12 shows a semiconductor device package according to an embodiment.

DETAILED DESCRIPTIONS

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.However, the technical idea of the present disclosure is not limited tosome embodiments as described, but may be implemented in variousdifferent forms. At least one of components in one embodiment may beselectively combined with or substituted with at least one of componentsin another embodiment, within the technical idea range of the presentdisclosure. Further, the terms used in the embodiment of the presentdisclosure (including technical and scientific terms) have meanings thatmay be generally understood by those of ordinary skill in the technicalfield to which the present disclosure belongs, unless explicitly definedand described. Commonly used terms such as terms defined in dictionariesmay be interpreted with considering contextual meaning thereof in therelated art. Further, the term used in the embodiment of the presentdisclosure is intended for describing embodiments and is not intended tolimit the present disclosure. As used herein, the singular forms “a” and“an” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. As used herein, the term “and/or”includes any and all combinations of at least one of the associatedlisted items. Expression such as “at least one of” when preceding a listof elements may modify the entire list of elements and may not modifythe individual elements of the list. It will be understood that,although the terms “first”, “second”, “third” and so on may be usedherein to describe various elements, components, regions, layers and/orsections, these elements, components, regions, layers and/or sectionsshould not be limited by these terms. These terms are used todistinguish one element, component, region, layer or section fromanother element, component, region, layer or section. Thus, a firstelement, component, region, layer or section described below could betermed a second element, component, region, layer or section, withoutdeparting from the spirit and scope of the present disclosure. It willbe understood that when an element or layer is referred to as being“connected to”, or “coupled to” another element or layer, it may bedirectly on, connected to, or coupled to the other element or layer, orat least one intervening elements or layers may be present. In addition,it will also be understood that when an element or layer is referred toas being “between” two elements or layers, it may be the only element orlayer between the two elements or layers, or at least one interveningelements or layers may also be present. In addition, it will also beunderstood that when a first element or layer is referred to as beingpresent “on” or “beneath” a second element or layer, the first elementmay be disposed directly on or beneath the second element or may bedisposed indirectly on or beneath the second element with a thirdelement or layer being disposed between the first and second elements orlayers.

Hereinafter, an embodiment for solving the above problems will bedescribed with reference to the accompanying drawings.

Further, as used herein, when an element is disposed “on” or “on a top”of another element, the former may directly contact the latter or stillanother element may be disposed between the former and the latter. Asused herein, when an element is directly disposed “on” or “on a top” ofanother element, the former directly contacts the latter and stillanother element is not disposed between the former and the latter.Further, as used herein, when an element is disposed “below” or “under”another element, the former may directly contact the latter or stillanother element may be disposed between the former and the latter. Asused herein, when an element is directly disposed “below” or “under”another element, the former directly contacts the latter and stillanother element is not disposed between the former and the latter.

The semiconductor device may include various electronic devicesincluding light-emitting devices and light-receiving devices. Each ofthe light-emitting device and the light-receiving device may include asemiconductor structure including at least a first semiconductor layer,an active layer, and a second semiconductor layer. The semiconductordevice according to an embodiment may be a light-emitting device. Thelight-emitting device may emit light via recombination between firstcarriers, that is, electrons and second carriers, that is, holes. Awavelength of the light may be determined based on a bandgap energyinherent to a material. Therefore, the emitted light may vary dependingon a composition of the material.

The light-emitting device may be referred to as a semiconductorlight-emitting device.

In a following description, a first dopant may be silicon (Si), and asecond dopant may be magnesium (Mg). However, the present disclosure isnot limited thereto.

As will be explained below, as illustrated in FIG. 7 , a fifthsemiconductor layer 23 may include a first layer 101 and a second layer103. The second semiconductor layer 25 may include a third layer 105. Anactive layer 21 may have a first recess 22. The active layer 21 mayinclude a fourth layer 107 and a fifth layer 109 formed in the firstrecess 22. For example, the fourth layer 107 may contact the first layer101. In another example, the fourth layer 107 and fifth layer 109 may beincluded in a conductive-type semiconductor layer including a seconddopant, such as the second semiconductor layer 25 or the fourthsemiconductor layer 23.

For example, the first to fifth layers 101, 103, 105, 107 and 109 mayinclude a dopant made of magnesium. Each of the first to fifth layers101, 103, 105, 107 and 109 may be defined based on a change in a dopingconcentration of the magnesium. However, the present disclosure is notlimited thereto. For example, the concentration of the dopant in thefirst layer 101 may increase in a first direction, the concentration ofthe dopant in the second layer 103 may decrease in the first direction,and the concentration of the dopant in the third layer 105 may increasein the first direction.

Each of the second semiconductor layer 25 and the fourth semiconductorlayer 23 may be referred to as a second conductive-type semiconductorlayer. The second conductive-type semiconductor layer may furtherinclude at least one semiconductor layer other than the secondsemiconductor layer 25 and the fourth semiconductor layer 23. However,the present disclosure is not limited thereto. In addition, each of thefirst semiconductor layer 15, the third semiconductor layer 17 and thefourth semiconductor layer 19 may be referred to as a firstconductive-type semiconductor layer.

The first direction as defined above may refer to a direction from thefirst conductive-type semiconductor layer to the second conductive-typesemiconductor layer.

For example, gradients of the concentration of the dopant in the firstto fifth layers 101, 103, 105, 107 and 109, respectively may bedifferent from each other.

The dopant made of the magnesium may not be contained in a remainingregion of the active layer 21 except the fourth layer 107 and the fifthlayer 109 disposed in the first recess 22. However, the presentdisclosure is not limited thereto.

For example, the concentration of the dopant in the fourth layer 107 maybe lower than that of the second layer 103. For example, the highestconcentration of the dopant in the second layer 103 may be 10 to 1000times larger than the highest concentration of the dopant in the fourthlayer 107. For example, the concentration of the dopant in the fourthlayer 107 may be lower by at least 10 times than the concentration ofthe dopant in the second layer 103.

For example, the concentration of the dopant in the fifth layer 109 maybe zero. That is, magnesium may not be present in the fifth layer 109 ofthe first recess 22.

For example, the concentration of the dopant in the fourth layer 107 maydecrease in a second direction, which is a direction opposite to thefirst direction.

For example, the concentration gradient of the dopant of the first layer101 and the concentration gradient of the dopant of the fourth layer 107may be different from each other.

For example, the concentration gradient of the dopant of the fourthlayer 107 may be lower than the concentration gradient of the dopant ofthe first layer 101.

For example, a minimum concentration of the dopant in the first layer101 may be equal to a maximum concentration of the dopant in the fourthlayer 107.

For example, a size of the first recess 22 may be increased in the firstdirection. For example, when a depth of the first recess 22 is constant,the concentration gradient of the dopant along the second direction mayvary based on a size of a topmost region of the first recess 22. Forexample, when a size of the topmost region of the first recess 22 isconstant, the concentration gradient of the dopant along the seconddirection may vary based on the depth of the first recess 22.

For example, the concentration of the dopant in the topmost region ofthe first recess 22 may be lower than the lowest concentration of thedopant in the second layer 103.

For example, the depth of the first recess 22 may be smaller than thethickness of the active layer 21.

For example, the first conductive-type semiconductor layer may include asecond recess 18, and the second recess 18 may overlap with the firstrecess 22 in the first direction.

Structure of Semiconductor Device

FIG. 1 shows a semiconductor device according to a first embodiment.

Referring to FIG. 1 , a semiconductor device 10 according to the firstembodiment may include the first semiconductor layer 15, the activelayer 21 disposed on the first semiconductor layer 15 and the secondsemiconductor layer 25 disposed on the active layer 21. Thesemiconductor device 10 according to the first embodiment may furtherinclude the third semiconductor layer 17 and the fourth semiconductorlayer 19 disposed between the first semiconductor layer 15 and theactive layer 21, and the fifth semiconductor layer 23 disposed betweenand the active layer 21 and the second semiconductor layer 25.

The fifth semiconductor layer 23 may include the first layer 101 and thesecond layer 103. The second semiconductor layer 25 may include thethird layer 105. The active layer 21 may have the first recess 22. Theactive layer 21 may include the fourth layer 107 and the fifth layer 109formed in the first recess 22. For example, the fourth layer 107 maycontact the first layer 101.

The first recess 22 may pass through the active layer 21, the fourthsemiconductor layer 19 and the third semiconductor layer 17 andterminate at a bottom of the third semiconductor layer 17 or at a pointabove the bottom. That is, a size of the recess 22 may be zero at thebottom of the third semiconductor layer 17 or at the point above thebottom.

The first semiconductor layer 15, the third semiconductor layer 17 andthe fourth semiconductor layer 19 may be referred to as the firstconductive-type semiconductor layer. The second semiconductor layer 25and the fourth semiconductor layer 23 may be referred to as the secondconductive-type semiconductor layer.

The first semiconductor layer 15, the active layer 21 and the secondsemiconductor layer 25 may constitute a semiconductor structure. Thesemiconductor structure may be referred to as a light emissionstructure. When an electrical signal is supplied to the semiconductorstructure, light corresponding to the electrical signal may be generatedand may be emitted from the semiconductor structure. The intensity ofthe light may be proportional to the intensity of the electrical signal.

The first semiconductor layer 15 may be, for example, an n-typesemiconductor layer, and the second semiconductor layer 25 may be ap-type semiconductor layer. However, the present disclosure is notlimited thereto. The n-type semiconductor layer may contain a firstcarrier as a majority carrier, for example, an electron. The p-typesemiconductor layer may contain a second carrier as a majority carrier,for example, a hole.

When an electrical signal is supplied to the semiconductor structure,the first carrier of the first semiconductor layer 15, and the secondcarrier of the second semiconductor layer 25 may be injected into theactive layer 21. In the active layer 21, the second carrier and thefirst carrier are recombined with each other to emit light of awavelength region corresponding to a bandgap energy of the active layer21. The bandgap energy may be determined based on the compoundsemiconductor material. For example, ultraviolet light or infrared lightmay be emitted depending on the compound semiconductor material of theactive layer 21.

In order to improve electrical and optical properties, at least onelayer may be disposed under the semiconductor structure, above thesemiconductor structure, and/or within the semiconductor structure.

For example, a buffer layer 13 may be disposed under the firstsemiconductor layer 15. For example, the third semiconductor layer 17,and the fourth semiconductor layer 19 may be disposed between the firstsemiconductor layer 15 and the active layer 21. For example, the fifthsemiconductor layer 23 may be disposed between the active layer 21 andthe second semiconductor layer 25.

The third semiconductor layer 17 may be a middle temperature (MT) layer.In this connection, the middle temperature may be a temperature forforming the third semiconductor layer 17. A growth temperature of thethird semiconductor layer 17 may be lower than a growth temperature ofthe first semiconductor layer 15.

In growth of the third semiconductor layer 17, vertical and horizontalgrowth rates may be controlled by adjusting a temperature, adjusting anindium (In) content, and adjusting a thickness of each sub-semiconductorlayer (see 17 a, and 17 b in FIG. 2 ), such that recesses 18 may beformed. For example, the recess 18 may have a V-pit shape.

A recess may be formed in each of the fourth semiconductor layer 19, theactive layer 21 and the fifth semiconductor layer 23 in a correspondingmanner to the recesses 18 formed in the third semiconductor layer 17.Each of the recess of the fourth semiconductor layer 19, the recess 22of the active layer 21, and the recess of the fifth semiconductor layer23 may have a shape corresponding to a shape of the recesses 18 formedin the third semiconductor layer 17. That is, as the recess 18 formed inthe third semiconductor layer 17 has a V-pit shape, each of the recessof the fourth semiconductor layer 19, the recess of the active layer 21,and the recess of the fifth semiconductor layer 23 may have a V-pitshape.

As shown in FIG. 1 , the lowest point of the recesses 18 of the thirdsemiconductor layer 17 may be located at a bottom face of the thirdsemiconductor layer 17.

The fourth semiconductor layer 19 may have a recess corresponding to therecess 18 of the third semiconductor layer 17. A partial region of thefourth semiconductor layer 19 may be disposed in recess 18 of the thirdsemiconductor layer 17.

The active layer 21 may have a recess 22 corresponding to a recess 18 ofthe third semiconductor layer 17 or a recess of the fourth semiconductorlayer 19.

A partial region of the active layer 21 may be disposed in the recess ofthe fourth semiconductor layer 19. Further, a partial region of theactive layer 21 may be disposed in the recess 18 of the thirdsemiconductor layer 17.

The fifth semiconductor layer 23 may have a recess corresponding to therecess 22 of the active layer 21. A partial region of the fifthsemiconductor layer 23 may be disposed in the recess 22 of the activelayer 21. Further, a partial region of the fifth semiconductor layer 23may be disposed in the recess of the fourth semiconductor layer 19. Inaddition, a partial region of the fifth semiconductor layer 23 may bedisposed in the recess 18 of the third semiconductor layer 17.

In one example, a partial region of the second semiconductor layer 25may be disposed in recess of the fifth semiconductor layer 23. Further,a partial region of the second semiconductor layer 25 may be disposed inthe recess 22 of the active layer 21. Further, a partial region of thesecond semiconductor layer 25 may be disposed in the recess of thefourth semiconductor layer 19. In addition, a partial region of thesecond semiconductor layer 25 may be disposed in the recess 18 of thethird semiconductor layer 17. Accordingly, a partial region of thesecond semiconductor layer 25 may pass through the fifth semiconductorlayer 23, the active layer 21 and the fourth semiconductor layer 19 andmay be disposed in the recess 18 of the third semiconductor layer 17. Inother words, a partial region of the second semiconductor layer 25 mayextend through the fifth semiconductor layer 23, the active layer 21,the fourth semiconductor layer 19 and the third semiconductor layer 18.

In this case, the fourth and the fifth layers 107 and 109 which areidentified based on the concentration of the second dopant therein maybe disposed in the recess 22 of the active layer 21.

As will be explained below, as shown in FIG. 7 , the fourth layer 107may contain a second dopant. The fifth layer 109 may not contain thesecond dopant. However, the present disclosure is not limited thereto.Further, the concentration of the second dopant included in the fourthlayer 107 may decrease in a direction from the top to the bottom of theactive layer 21.

The second dopant of the fourth layer 107 may be the same as the dopantincluded in the second semiconductor layer 25. Further, the seconddopant of the fourth layer 107 may be formed via diffusion of the dopantincluded in the second semiconductor layer 25 into the recess 22 of theactive layer 21. However, the present disclosure is not limited thereto.

All of the lowest point of the recess of the fifth semiconductor layer23, the lowest point of the recess 22 of the active layer 21, and thelowest point of the recess of the fourth semiconductor layer 19 maycoincide with the lowest point of the recess 18 of the thirdsemiconductor layer 17. In this case, the lowest point of the partialregion of the second semiconductor layer 25 may contact a top face ofthe first semiconductor layer 15. However, the present disclosure is notlimited thereto.

As shown in FIG. 1 , a partial region of the fourth semiconductor layer19, a partial region of the active layer 21 and a partial region of thefifth semiconductor layer 23 may not be disposed in the recess 18 formedin the third semiconductor layer 17. A partial region of the secondsemiconductor layer 25 may be disposed in the recess 18 formed in thethird semiconductor layer 17. In this case, the partial region of thesecond semiconductor layer 25 may contact the bottom of the recess 18formed in the third semiconductor layer 17.

The recess 18 may have a size or width that increases as the recessextends from a bottom of the third semiconductor layer 17 to a topthereof. A lateral face of the recess 18 may have a straight face.However, the present disclosure is not limited thereto.

The fourth semiconductor layer 19 may act as a strain relaxation layer(SRL) or a current spreading layer (CSL). The fourth semiconductor layer19 may rapidly spread the current along a horizontal direction. Thefourth semiconductor layer 19 may relax stress to prevent defects suchas cracks in the semiconductor device 10.

The fifth semiconductor layer 23 may act as a carrier blocking layer(EBL). The fifth semiconductor layer 23 may prevent the first carrierinjected from the first semiconductor layer 15 to the active layer 21from passing through the active layer 21 and then moving to the secondsemiconductor layer 25.

Typically, mobility of the first carrier may be 10 to 1000 times higherthan mobility of the second carrier. Therefore, a probability ofnon-light-emitting type recombination in which the first carrierinjected from the first semiconductor layer 15 to the active layer 21passes through the active layer 21 and then may be injected into thesecond semiconductor layer 25 and may be recombined with the secondcarrier therein may be higher than probability of light-emitting typerecombination in which the first carrier injected from the firstsemiconductor layer 15 to the active layer 21 will be recombined withthe second carrier injected from the second semiconductor layer 25 tothe active layer 21. Thus, as the probability of the non-light-emittingtype recombination in which the first carrier injected from the firstsemiconductor layer 15 to the active layer 21 passes through the activelayer 21 and then may be injected into the second semiconductor layer 25and may be recombined with the second carrier therein is higher, lightgeneration efficiency may be lowered, and eventually the luminousintensity may be lowered.

Therefore, placing the fifth semiconductor layer 23 between the activelayer 21 and the second semiconductor layer 25 may disallow the firstcarrier injected from the first semiconductor layer 15 to the activelayer 21 to be moved to the second semiconductor layer 25, such that theluminous intensity may be increased.

These semiconductor layers, that is, the buffer layer 13, the first tofifth semiconductor layers 15, 25, 17, 19, and 23, and the active layer21 may be disposed over a substrate 11. In other words, the buffer layer13, the first semiconductor layer 15, the third semiconductor layer 17,the fourth semiconductor layer 19, the active layer 21, the fifthsemiconductor layer 23, and the second semiconductor layer 25 may besequentially grown over the substrate 11 using a deposition process.That is, the substrate 11 may be loaded in a chamber of a depositionapparatus, and then the buffer layer 13, the first semiconductor layer15, the third semiconductor layer 17, the fourth semiconductor layer 19,the active layer 21, the fifth semiconductor layer 23, and the secondsemiconductor layer 25 are sequentially grown thereon. In this way, thesemiconductor device 10 according to the first embodiment may bemanufactured. Subsequently, the substrate 11 may be taken out of thechamber of the deposition apparatus.

The deposition apparatus may include, for example, a MOCVD (MetalOrganic Chemical Vapor Deposition) apparatus, a CVD (Chemical VaporDeposition) apparatus, a PECVD (Plasma-Enhanced Chemical VaporDeposition) apparatus, a MBE (Molecular Beam Epitaxy) apparatus, and aHVPE (Hydride Vapor Phase Epitaxy) apparatus. However, the presentdisclosure is not limited thereto.

Material Characteristics of Semiconductor Device 10

Over the substrate 11, the buffer layer 13, the first semiconductorlayer 15, the third semiconductor layer 17, the fourth semiconductorlayer 19, the active layer 21, and the fifth semiconductor layer 23, andthe second semiconductor layer 25 may be grown over a substrate. Thesubstrate may support the buffer layer 13, the first semiconductor layer15, the third semiconductor layer 17, the fourth semiconductor layer 19,the active layer 21, the fifth semiconductor layer 23, and the secondsemiconductor layer 25 thereon.

To those ends, the substrate 11 may be made of a material suitable forgrowth of a group III-V compound semiconductor material or a group II-VIcompound semiconductor material. The substrate 11 may be made of, forexample, a material having at least thermal stability, and a similarlattice constant to that of the first semiconductor layer 15.

For example, the substrate 11 may be a conductive substrate or aninsulating substrate. For example, the substrate 11 may be made of atleast one selected from a group consisting of sapphire (Al₂O₃), SiC, Si,GaAs, GaN, ZnO, GaP, InP, and Ge.

The buffer layer 13 may be disposed on the substrate 11. The bufferlayer 13 may play a role in reducing a difference between latticeconstants of the substrate 11 and the first semiconductor layer 15.Since the difference between the lattice constants of the substrate 11and the first semiconductor layer 15 is reduced using the buffer layer13, the first semiconductor layer 15, the third semiconductor layer 17,the fourth semiconductor layer 19, the active layer 21, the fifthsemiconductor layer 23, and the second semiconductor layer 25 may bestably grown on the substrate 11 while defects are not created. Thebuffer layer 13 may include a group III-V compound semiconductormaterial or a group I-VI compound semiconductor material.

The first semiconductor layer 15 may be disposed on the buffer layer 13.When the buffer layer 13 is omitted, the first semiconductor layer 15may be disposed on the substrate 11.

The first semiconductor layer 15 may be made of a compound semiconductormaterial of Al_(x)In_(y)Ga_((1-x-y))N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). However,the present disclosure is not limited thereto. For example, the firstsemiconductor layer 15 may include at least one selected from a groupconsisting of InAlGaN, GaN, AlGaN, InGaN, AlN, InN, AlInN, GaAs, AlGaAs,GaAsP GaP, InP, GaInP, and AlGaInP. However, the present disclosure isnot limited thereto.

The first semiconductor layer 15 may have a thickness of about 1 m toabout 10 μm.

The first semiconductor layer 15 may contain n-type dopants such as Si,Ge, Sn, Se, and Te. A doping concentration thereof, for example, asilicon (Si) concentration in the first semiconductor layer 15 may be ina range of about 5×10¹⁸ cm⁻³ to about 3×10¹⁹ cm⁻³. In this concentrationrange, an operation voltage, and an epitaxy quality may be improved.

The first semiconductor layer 15 may feed the first carrier to theactive layer 21.

The first semiconductor layer 15 may include carbon (C). A carbon (C)concentration in the first semiconductor layer 15 may be 1×10¹⁶ cm⁻³ to4×10¹⁶ cm⁻³. When the carbon (C) concentration in the firstsemiconductor layer 15 may be 1×10¹⁶ cm⁻³ or greater, the reliability ofthe semiconductor device may be improved. When the carbon (C)concentration in the first semiconductor layer 15 may be 4×10¹⁶ cm⁻³ orlower, the operating voltage thereof may be improved in thisconcentration range.

The third semiconductor layer 17 may be disposed on the firstsemiconductor layer 15. The fourth semiconductor layer 19 may bedisposed on the third semiconductor layer 17.

Each of the third semiconductor layer 17 and the fourth semiconductorlayer 19 may be made of a compound semiconductor material ofAl_(x)In_(y)Ga_((1-x-y))N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). However, the presentdisclosure is not limited thereto.

Each of the third semiconductor layer 17 and the fourth semiconductorlayer 19 may have a superlattice structure composed of a plurality oflayers. For example, each of the third semiconductor layer 17 and thefourth semiconductor layer 19 may include an InGaN/GaN stack structureor an InGaN/AlGaN stack structure. However, the present disclosure isnot limited thereto.

An indium (In) content of the third semiconductor layer 17 may be in arange of about 1% to about 3%. In this content range, the recess 18 suchas the V-pit may be more easily formed, and a film having an uniformthickness may be obtained.

When the fourth semiconductor layer 19 acts as a stress relaxationlayer, an indium (In) content therein may be in a range of about 3% toabout 6%. The current may be quickly spread in this content range.

When the fourth semiconductor layer 19 acts as the current spreadinglayer, the indium (In) content therein may be in a range of about 6% toabout 12%. The stress may be relaxed in this content range. Further,defects such as cracks may be suppressed in the semiconductor device 10in this content range.

The fourth semiconductor layer 19 may act as only one of the stressrelaxation layer and the current spreading layer. Alternatively, thefourth semiconductor layer 19 may act as both the stress relaxationlayer and the current spreading layer.

A thickness of the third semiconductor layer 17 may be in a range ofabout 130 nm to about 170 nm.

The third semiconductor layer 17 may contain n-type dopants such as Si,Ge, Sn, Se, and Te. A doping concentration, for example, a silicon (Si)concentration in the third semiconductor layer 17 may be in a range ofabout 8×10¹⁷ cm⁻³ to about 2×10¹⁸ cm⁻³. In this concentration range, theoperation voltage, and the epitaxy quality may be improved.

The fourth semiconductor layer 19 may include n-type dopants such as Si,Ge, Sn, Se, and Te. A doping concentration, for example, a silicon (Si)concentration in the fourth semiconductor layer 19 may be in a range ofabout 1×10¹⁷ cm⁻³ to about 1×10¹⁸ cm⁻³. In this concentration range, theoperation voltage, and the epitaxy quality may be improved.

The third semiconductor layer 17 may contain carbon (C). A carbonconcentration in the third semiconductor layer 17 may be in a range ofabout 6×10¹⁶ cm⁻³ or lower. The operating voltage may be improved inthis concentration range.

The fourth semiconductor layer 19 may contain carbon (C). A carbonconcentration in the fourth semiconductor layer 19 may be in a range ofabout 6×10¹⁶ cm⁻³ or lower. The operating voltage may be improved inthis concentration range.

A ratio between the carbon concentration and the silicon (Si)concentration in the third semiconductor layer 17 may be in a range ofabout 1:80 to about 1:200.

When the ratio between the carbon concentration and the siliconconcentration is 1:80 or greater, electrical resistance of the carbonmay be canceled by the silicon (Si), so that the operation voltage maybe improved. When the ratio between the carbon concentration and thesilicon concentration is 1:200 or smaller, movement of the first carriergenerated in the first semiconductor layer 15 may not be disturbed bythe silicon (Si), such that the luminous intensity may be increased.

Although not shown, an electron injection layer that facilitatesinjection of the first carrier generated in the first semiconductorlayer 15 into the active layer 21 may be further disposed between thethird semiconductor layer 17 and the active layer 21 or between thefourth semiconductor layer 19 and the active layer 21.

The active layer 21 may be disposed on the first semiconductor layer 15,the third semiconductor layer 17 or the fourth semiconductor layer 19.

The active layer 21 may perform electro luminescence (EL) in which anelectrical signal applied across the first semiconductor layer 15 andthe second semiconductor layer 25 is converted into light. That is, theactive layer 21 may generate light of a specific wavelength region inresponse to the electrical signal. The light of the specific wavelengthregion may not be generated by itself but may be generated only when theelectrical signal is applied across the first semiconductor layer 15 andthe second semiconductor layer 25.

The active layer 21 may include one of a multi-quantum well structure(MQW), a quantum dot structure, or a quantum wire structure. The activelayer 21 may include a stack structure in which a well layer and abarrier layer may be repeatedly alternately stacked one on top of theother.

A repeating number of the well layer and the barrier layer may bemodified based on characteristics of the semiconductor device 10.However, the present disclosure is not limited thereto. For example, therepeating number of the well layer and the barrier layer may be in arange of 1 to 20. However, the present disclosure is not limitedthereto.

The active layer 21 may include the well layer/the barrier layer such asInGaN/InGaN, InGaN/GaN, or InGaN/AlGaN.

An indium (In) content in the active layer 21 may be in a range of about12% to about 16%. Light of a main light-emitting peak wavelength, forexample, blue wavelength light may be generated in the content range.

The well layer may have a thickness of about 1 nm to about 10 nm, andthe barrier layer may have a thickness of about 1 nm to about 20 nm.

The p-type dopant may be contained in the well layer and/or the barrierlayer of the active layer 21.

The fifth semiconductor layer 23 may be disposed on the active layer 21.The fifth semiconductor layer 23 may be made of a compound semiconductormaterial of Al_(x)In_(y)Ga_((1-x-y))N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). However,the present disclosure is not limited thereto.

The fifth semiconductor layer 23 may have a superlattice structurecomposed of a plurality of layers. For example, the fifth semiconductorlayer 23 may include a repetition of a stack structure such as arepetition of an AlGaN/GaN stack structure. However, the presentdisclosure is not limited thereto.

For example, an aluminum (Al) content in the fifth semiconductor layer23 may be in a range of about 15% to about 24%. In this content range,blocking performance of the first carrier may be improved, and theinjection efficiency in which the second carrier of the secondsemiconductor layer 25 is injected into the active layer 21 may beimproved.

The fifth semiconductor layer 23 may contain p-type dopants such as Mg,Zn, Ca, Sr, and Ba. A doping concentration, for example, theconcentration of the second dopant in the fifth semiconductor layer 23may be in a range of about 5×10¹⁸ cm⁻³ to about 1×10²⁰ cm⁻³. Theoperation voltage may be improved, and the light output may be improvedin this doping concentration range.

Although not shown, a hole injection layer that facilitates injection ofthe second carrier generated in the second semiconductor layer 25 intothe active layer 21 may be further disposed between the active layer 21and the fifth semiconductor layer 23. For example, the hole injectionlayer may include GaN. However, the present disclosure is not limitedthereto.

The second semiconductor layer 25 may be disposed on the active layer 21or the fifth semiconductor layer 23. The second semiconductor layer 25may feed the second carrier to the active layer 21.

The second semiconductor layer 25 may be made of a compoundsemiconductor material of Al_(x)In_(y)Ga_((1-x-y))N (0≤x≤1, 0≤y≤1,0≤x+y≤1). However, the present disclosure is not limited thereto. Forexample, the second semiconductor layer 25 may include at least oneselected from a group consisting of InAlGaN, GaN, AlGaN, InGaN, AlN,InN, AlInN, GaAs, AlGaAs, GaAsP GaP, InP, GaInP, and AlGaInP. However,the present disclosure is not limited thereto.

The second semiconductor layer 25 may have a thickness of about 1 m orsmaller.

The second semiconductor layer 25 may contain p-type dopants such as Mg,Zn, Ca, Sr, and Ba. A doping concentration, for example, a concentrationof the second dopant in the second semiconductor layer 25 may be in arange of about 5×10¹⁸ cm⁻³ to about 5×10²⁰ cm⁻³. The operation voltagemay be improved, and the light output may be improved in this dopingconcentration range.

Detailed Structure of Third Semiconductor Layer

FIG. 2 shows the third semiconductor layer in detail.

Referring to FIG. 2 , the third semiconductor layer 17 may be composedof a first pair, a second pair, and a third pair. However, the presentdisclosure is not limited thereto. In other words, the thirdsemiconductor layer 17 may be composed of at least four pairs.

Each of the first pair, the second pair, and the third pair may includea first sub-semiconductor layer 17 a and a second sub-semiconductorlayer 17 b. Accordingly, a top face of the second sub-semiconductorlayer 17 b of the first pair may be in contact with a bottom face of thefirst sub-semiconductor layer 17 a of the second pair. A top face of thesecond sub-semiconductor layer 17 b of the second pair may contact abottom face of the first sub-semiconductor layer 17 a of the third pair.

For example, a bottom face of the first sub-semiconductor layer 17 a ofthe first pair may be in contact with a top face of the firstsemiconductor layer 15, a top face of the second sub-semiconductor layer17 b of the third pair may contact a bottom face of the fourthsemiconductor layer 19. However, the present disclosure is not limitedthereto.

For example, the first sub-semiconductor layer 17 a may made of GaN. Forexample, the second sub-semiconductor layer 17 b may be made of InGaN.That is, the indium (In) may be contained in the first sub-semiconductorlayer 17 a. The indium (In) may not be contained in the secondsub-semiconductor layer 17 b. Accordingly, the indium (In) may becontained in the third semiconductor layer 17 periodically, for example,on a pair basis.

The third semiconductor layer 17 may be grown on the first semiconductorlayer 15 at a temperature of about 830° C. to about 870° C.

For example, in a state in which trimethylgallium (TMG) gas, andnitrogen (N₂) gas are injected into the chamber of the MOCVD apparatus,the indium (In) may be periodically injected thereto. Thus, the firstsub-semiconductor layers 17 a, and the second sub-semiconductor layer 17b of each of the first pair, the second pair, and the third pair may begrown. While the indium (In) is not injected thereto, the firstsub-semiconductor layer 17 a made of GaN may be grown using the TMG gas,and the nitrogen gas. Subsequently, while the indium (In) is injectedthereto, the second sub-semiconductor layer 17 b made of InGaN may begrown using a mixture of the indium (In) with the TMG gas, and thenitrogen gas.

For example, a thickness T1 of the first sub-semiconductor layer 17 amay be in a range of about 15 nm to about 40 nm. For example, athickness T2 of the second sub-semiconductor layer 17 b may be in arange of about 2 nm to about 5 nm.

A ratio between the thickness of the second sub-semiconductor layer 17 band the thickness of the first sub-semiconductor layer 17 a may be in arange of about 1:3 to about 1:8. In this thickness range, a growth ratein vertical and horizontal directions of the third semiconductor layer17 may be controlled, so that the recess 18 such as the V-pit may beeasily formed.

The lowest point of the recess 18 may coincide with the bottom face ofthe first sub-semiconductor layer 17 a of the first pair.

For example, an angle between a normal line and an inclined lateral faceof the recess 18 may be defined as an inclination angle θ₁. Theinclination angle θ₁ may be 5 to 30°. When the inclination angle θ₁ isgreater than or equal to 5°, the luminous intensity of light emittedfrom the semiconductor device may be increased. When the inclinationangle θ₁ is greater than or equal to 30°, this may be preferable interms of the luminous intensity. However, there is a limitation inincreasing the inclination angle θ₁ relative to a thickness of the thirdsemiconductor layer 17.

When the ratio between the thickness of the second sub-semiconductorlayer 17 b and the thickness of the first sub-semiconductor layer 17 ais smaller than 1:3 or is greater than 1:8, an arrangement density ofthe recesses 18 or the inclination angle of the inclined face of therecess 18 may change, resulting in deterioration of the light output,the operation voltage, and ESD (Electro Static Discharge)characteristics of the semiconductor device 10. The arrangement densitythereof may refer to a distribution probability of the recesses 18.

In FIG. 2 , the recess 18 is shown to start to extend from the secondsub-semiconductor layer 17 b of the first pair. However, the presentdisclosure is not limited thereto. A starting position of the extensionof the recess 18 or a bottom position of thereof may vary.

The recess 18 of the third semiconductor layer 17 may improve theelectrical and optical characteristics of the semiconductor device 10.However, when the recesses 18 are highly densely arranged, that is, whenthe arrangement density of the recess 18 is excessive, the electricaland optical characteristics, and reliability of the semiconductor device10 may be deteriorated. Therefore, controlling the arrangement densityof the recesses 18, and the size of the recess 18 may allow improvingthe optical and electrical characteristics of the semiconductor device10, and securing the reliability thereof.

As shown in FIG. 2 , a width Wi or a size of the recess 18 may increaseas the recess extends from a bottom to a top of the third semiconductorlayer 17. In this case, in the topmost region of the secondsub-semiconductor layer 17 b of the third pair, a maximum width Wi ofthe recess 18 may be obtained.

The first semiconductor layer 15 may be grown, for example, at atemperature of about 1000° C. to 1,100° C. In this case, the thirdsemiconductor layer 17 may be grown at a temperature (that is, about830° C. to about 870° C.) lower than the growth temperature of the firstsemiconductor layer 15. Further, the first and second sub-semiconductorlayers 17 a and 17 b included in each pair of the third semiconductorlayer 17 may be grown to have different thicknesses from each other. Inaddition, the indium (In) may be selectively contained in the first andsecond sub-semiconductor layers 17 a and 17 b of each pair of the thirdsemiconductor layer 17. Therefore, as the first sub-semiconductor layer17 a and the second sub-semiconductor layer 17 b of the thirdsemiconductor layer 17 are periodically grown while performing thetemperature adjustment, the thickness adjustment, and the adjustment ofthe indium (In) content, the formation of the recess 18 such as theV-pit may be facilitated and may be precisely controlled.

Detailed Structure of Fifth Semiconductor Layer

FIG. 3 shows the fifth semiconductor layer in detail.

Referring to FIG. 3 , the fifth semiconductor layer 23 may be composedof a first pair, a second pair, and a third pair. However, the presentdisclosure is not limited thereto.

Each of the first pair, the second pair, and the third pair may includea first sub-semiconductor layer 23 a and each of secondsub-semiconductor layers 23 b, 23 c and 23 d. Accordingly, a top face ofthe second sub-semiconductor layer 23 b of the first pair may be incontact with a bottom face of the first sub-semiconductor layer 23 a ofthe second pair. a top face of the second sub-semiconductor layer 23 cof the second pair may contact the bottom face of the firstsub-semiconductor layer 23 a of the third pair.

For example, a bottom face of the first sub-semiconductor layer 23 a ofthe first pair may be in contact with a top face of the active layer 21.A top face of the second sub-semiconductor layer 23 d of the third pairmay contact a bottom face of the second semiconductor layer 25. However,the present disclosure is not limited thereto.

For example, the first sub-semiconductor layer 23 a may be made of GaN.Each of the second sub-semiconductor layers 23 b, 23 c, and 23 d may bemade of AlGaN.

Aluminum (Al) contents in the second sub-semiconductor layers 23 b, 23c, and 23 d of the first pair, the second pair, and the third pairrespectively may be different from each other.

For example, the second sub-semiconductor layer 23 b of the first pairmay include an Al_(x)Ga_(1-x)N/GaN stack, the second sub-semiconductorlayer 23 c of the second pair may include Al_(y)Ga_(1-y)N, and thesecond sub-semiconductor layer 23 d of the third pair may includeAl_(z)Ga_(1-z)N. In this case, a relationship between x, y, and z maysatisfy following Equation 1 and Equation 2.y=x−0.03,  [Equation 1]z=y−0.03  [Equation 2]

x may be in a range of 0.21 to 0.24.

For example, when x is 0.24, the aluminum (Al) content of the secondsub-semiconductor layer 23 b of the first pair may be 24%, the aluminum(Al) content of the second sub-semiconductor layer 23 c of the secondpair may be 21%, and the aluminum (Al) content of the secondsub-semiconductor layer 23 d of the third pair may be 18%.

For example, when x is 0.21, the aluminum (Al) content of the secondsub-semiconductor layer 23 b of the first pair may be 21%, the aluminum(Al) content of the second sub-semiconductor layer 23 c of the secondpair may be 18%, the aluminum (Al) content of the secondsub-semiconductor layer 23 d of the third pair may be 15%.

Accordingly, each of the aluminum (Al) contents of the secondsub-semiconductor layers 23 b, 23 c, and 23 d of the first pair, thesecond pair, and the third pair respectively of the fifth semiconductorlayer 23 may be adjusted to a value in a range of about 15% to about24%. In this content range, the blocking performance of the firstcarrier may be improved, and the injection efficiency in which thesecond carrier of the second semiconductor layer 25 is injected into theactive layer 21 may be improved.

The luminous intensity Po of the semiconductor device 10 variesdepending on the aluminum (Al) content, as shown in FIG. 4 .

FIG. 4 shows the luminous intensity based on the aluminum (Al) contentof the fifth semiconductor layer.

Referring to FIG. 4 , it may be identified that when the aluminum (Al)content is 24%, the luminous intensity Po is the highest. It may beidentified that when the aluminum (Al) content is smaller or greaterthan 24%, the luminous intensity Po is lowered.

The aluminum (Al) content of the second sub-semiconductor layer 23 b ofthe first pair may be in a range of about 21% to 24%. The aluminum (Al)content of the second sub-semiconductor layer 23 c of the second pairmay be in a range of about 18% to about 21%. The aluminum (Al) contentof the second sub-semiconductor layer 23 d of the third pair may be in arange of about 15% to about 18%. As described above, the aluminum (Al)contents of the second sub-semiconductor layers 23 c, and 23 d of thesecond pair, and the third pair respectively may be determined based onthe above Equation 1 and Equation 2.

When the aluminum (Al) content is smaller than 21%, the first carrieroverflows from the active layer 21 to the second semiconductor layer 25,such that light loss may occur due to leakage current. When the aluminum(Al) content exceeds 24%, the second carrier is not easily injected fromthe second semiconductor layer 25 into the active layer 21, such thatthe operation voltage may increase.

In one example, a deep hole injection effect may be achieved using therecess 22 formed in the active layer 21.

FIG. 5 shows a deep hole injection in a semiconductor device accordingto an embodiment.

As shown in FIG. 5 and FIG. 7 , the active layer 21 may have the recess22. The recess 22 in the active layer 21 may be formed in acorresponding manner to the recess 18 formed in the third semiconductorlayer 17.

The fifth semiconductor layer 23 and the second semiconductor layer 25may be sequentially disposed over the active layer 21.

A partial region of the second semiconductor layer 25 may be disposed inthe fourth layer 107. That is, the fourth layer 107 and the fifth layer109 may be disposed in the recess 21.

When an electrical signal is applied, the second carrier of the secondsemiconductor layer 25 may be injected into the active layer 21. Asdescribed above, the fifth semiconductor layer 23 blocks the firstcarrier of the first semiconductor layer 15 from being moved to thesecond semiconductor layer 25 through the active layer 21, while thefifth semiconductor layer 23 allows the second carrier of the secondsemiconductor layer 25 to be easily injected to the active layer 21.

The second carrier of the second semiconductor layer 25 may be injectedfrom the second semiconductor layer 25 to the active layer 21.

In addition, the second carrier may be generated in the fourth layer 107disposed in the recess 22. The second carrier generated in the fourthlayer 107 disposed in the recess 22 may also be injected into the activelayer 21 through the inclined face of the fourth layer 107.

As described above, the mobility of the first carrier is much higherthan that of the second carrier, such that the first carrier may beinjected into the active layer 21 in a larger amount than the secondcarrier may be, for the same time duration. In this case, only an amountof the first carrier corresponding to the same amount of the secondcarrier contributes to light generation via recombination therebetween,such that many first carriers are not recombined with the second carrierinjected from the second semiconductor layer 25.

However, in one embodiment, not only the second carrier of the secondsemiconductor layer 25 may be injected into the active layer 21 in thevertical direction, but also the second carriers may be injected intothe active layer 21 through the inclined face of the fourth layer 107.Thus, the second carriers may be injected into the active layer 21 in alarger amount.

Therefore, the second carriers may be injected into the active layer 21in the increased amount to increase the recombination amount between thefirst carrier and the second carrier for the same time duration, therebyimproving light efficiency and increasing luminous intensity.

In general, a recess such as a V-pit is exceedingly small. Thus, it isdifficult to identify whether the recess exists in the correspondingsemiconductor device.

In one embodiment, the recess may be easily identified based on changein the concentration of the dopant of the second semiconductor layer 25.Further, the size or the depth of the recess may be identified based onchange in the concentration of the dopant of the second semiconductorlayer 25.

The recess identification method will be described in detail withreference to FIG. 6 to FIG. 8 .

As shown in FIG. 6 to FIG. 8 , the composition or the dopingconcentration of each layer of the semiconductor device 10 asmanufactured as described above may be detected using the ion detectionmethod using a secondary ion analysis device.

FIG. 6 shows a second carrier profile when each layer, that is, each ofthe third semiconductor layer 17, the fourth semiconductor layer 19, theactive layer 21 and the fifth semiconductor layer 23 is free of therecess.

FIG. 7 shows the second carrier profile when each layer has the recess.FIG. 8 shows the second carrier profile when the density of the recessesis excessive. Magnesium may be used as the second carrier for the secondcarrier profile. However, the present disclosure is not limited thereto.That is, another p-type dopant doped into the second semiconductor layer25 may be applied as the second carrier.

As described above, each of the fifth semiconductor layer 23 and thesecond semiconductor layer 25 may include the p-type dopant such as themagnesium.

In this case, as shown in FIG. 6 , the concentration of the seconddopant has a significant value in each of the fifth semiconductor layer23 and the second semiconductor layer 25. However, the second dopantdoes not exist in the layers below the second semiconductor layer 25,that is, the active layer 21, the fourth semiconductor layer 19 and thelike.

In particular, when the recess 18 is not formed in the thirdsemiconductor layer 17, the recesses may not be formed in the fourthsemiconductor layer 19, the active layer 21 and the fifth semiconductorlayer 23 disposed over the third semiconductor layer 17. In this case,when measuring the secondary ions using a secondary ion analysis device,the concentration of the second dopant in the active layer 21 and thefourth semiconductor layer 19 disposed below the second semiconductorlayer 25 may be zero.

Therefore, this scheme may easily identify whether the recess is notformed in the layer of the semiconductor device 10 using the secondaryion analysis device.

To the contrary, as shown in FIG. 7 , the concentration of the seconddopant in the second semiconductor layer 25 disposed in the fourth layer107, that is, the fourth layer 107 may be detected.

As shown in FIG. 1 , the recess 22 recessed from the top face of theactive layer 21 may be formed and the second semiconductor layer 25 maybe disposed in the recess 22. Thus, a portion of the secondsemiconductor layer 25 in the fourth layer 107 may have the samevertical level as that of the active layer 21.

Therefore, the concentration of the second dopant may be detected in thefourth layer 107 disposed in the recess 22 in the active layer 21 andthe fourth layer 107 positioned on the same line. However, the magnesiummay not be detected in a remaining region of the active layer 21 exceptfor the recess 22.

As shown in FIG. 7 , the concentration of the second dopant detected inthe fourth layer 107 may be decreased along the thickness direction ofthe active layer 21, that is, the vertical direction. In other words,the concentration of the second dopant in the fourth layer 107 maydecrease in a direction from the top to the bottom of the active layer21. That is, the concentration of the second dopant of the fourth layer107 in the recess 22 may decrease in a direction from the top to thebottom of the active layer 21.

The concentration of the second dopant in the fourth layer 107 may havea gradient. The gradient of the concentration of the second dopant mayvary depending on the shape of the fourth layer 107. That is, thegradient of the concentration of the second dopant may vary depending ona size (or an area) or a depth of the recess 22 and/or a size or a depthof the fourth layer 107 disposed in the recess 22.

For example, when the depth of the fourth layer 107 is constant, thegradient of the concentration of the second dopant may decrease as thesize of the fourth layer 107 decreases along the thickness direction ofthe active layer 21.

FIG. 9 shows the gradient of the concentration of the second dopantbased on the size of the top region of recess 22, that is, the topmostregion of the fourth layer 107. In FIG. 9 a , a size of the topmostregion Ts of the fourth layer 107 may be X1, and in FIG. 9 b , a size ofthe topmost region Ts of the fourth layer 107 may be X2, and X2 may begreater than X1. The size may refer to an area of the topmost region Tsof the fourth layer 107 disposed in the recess 22.

The topmost region Ts of the fourth layer 107 may have the same verticallevel as that of a last well layer of the active layer 21. However, thepresent disclosure is not limited thereto. The last well layer of theactive layer 21 may be adjacent to the second semiconductor layer 25when the fifth semiconductor layer 23 or the fifth semiconductor layer23 is omitted.

As shown in FIG. 9 a , when a size of the topmost region Ts of thefourth layer 107 is X1, the concentration of the second dopant detectedin the topmost region Ts of the fourth layer 107 may be A1, and theconcentration of the second dopant may be reduced with staring from thetopmost region Ts of the fourth layer 107, so that the concentration ofthe second dopant may be zero in the bottommost region Te of the fourthlayer 107. A dimension between the top region and the bottom region maybe defined as a depth of the fourth layer 107. The bottommost region Teof the fourth layer 107 may be a bottom point of the fourth layer 107.Therefore, the gradient when the size of the topmost region Ts of thefourth layer 107 is X1 may be expressed as a following Equation 3.s1=A1/(Ts−Te)  [Equation 3]

As shown in FIG. 9 b , when the size of the topmost region Ts of thefourth layer 107 is X2, the concentration of the second dopant detectedin the topmost region Ts of the fourth layer 107 may be A2, and theconcentration of the second dopant may be reduced with staring from thetopmost region Ts of the fourth layer 107, so that the concentration ofthe second dopant detected in the bottommost region Te of the fourthlayer 107 may be zero. Therefore, the gradient when the size of thetopmost region Ts of the fourth layer 107 is X2 may be expressed as afollowing Equation 4.s2=A2/(Ts−Te)  [Equation 4]

The gradient of the concentration of the second dopant calculated fromthe Equation 3 and the Equation 4 may vary based on the size of thetopmost region Ts of the fourth layer 107.

When the depth of the fourth layer 107 is constant, the gradient of theconcentration of the second dopant detected in the fourth layer 107 maybe increased as the size of the topmost region Ts of the recess 22increases. That is, a second gradient s2 may be greater than a firstgradient S1 s 1.

This is because as the size of the topmost region Ts of the fourth layer107 increases, the concentration of the second dopant detected in thetopmost region Ts having the increased size increases.

In addition, when the size of the topmost region Ts of the fourth layer107 is constant, the gradient of the concentration of the second dopantmay vary depending on the depth of the fourth layer 107.

For example, the gradient of the concentration of the second dopant mayincrease as the depth of the fourth layer 107 decreases along thethickness direction of the active layer 21.

FIG. 10 shows the gradient of the concentration of the second dopantbased on the depth of the recess in the active layer. In FIG. 10 a , thedepth of the fourth layer 107 may be (Ts-Te1), and in FIG. 9 b , thedepth of the fourth layer 107 may be (Ts−Te2), and (Ts−Te2) may begreater than (Ts−Te1).

As shown in FIG. 10 a , when the depth of the fourth layer 107 is(Ts−Te1), the concentration of the second dopant may decrease from A tozero in a direction from the topmost region Ts of the fourth layer 107to the lowest region Te1 of the fourth layer 107. The first depth(Ts−Te1) may be the distance between the topmost region Ts of the fourthlayer 107 and the lowest region Te1 of the fourth layer 107. When thedepth of the fourth layer 107 is the first depth (Ts-Te1), the gradientmay be expressed as a following Equation 5.s1=A/(Ts−Te1)  [Equation 5]

As shown in FIG. 10 b , when the depth of the fourth layer 107 is(Ts−Te2), the concentration of the second dopant may decrease from A tozero in a direction from the topmost region Ts of the fourth layer 107to the bottommost region Te2 of the fourth layer 107. The second depth(Ts−Te2) may be a distance between the topmost region Ts of the fourthlayer 107 and the lowest region Te2 of the fourth layer 107. When thedepth of the fourth layer 107 is the second depth (Ts−Te2), the gradientmay be expressed as a following Equation 6.s2=A/(Ts−Te2)  [Equation 6]

The gradient of the concentration of the second dopant calculated fromthe Equation 5 and Equation 6 may vary based on the distance between thetop region Ts of the fourth layer 107 and the bottom region Te of thefourth layer 107.

When the size of the topmost region Ts of the fourth layer 107 isconstant, the gradient of the concentration of the second dopantdetected in the fourth layer 107 may be increased as the distancebetween the topmost region Ts of the fourth layer 107 and the bottommostregion Te of the fourth layer 107 is smaller. That is, the firstgradient s1 may be greater than the second gradient s2.

In an embodiment, the concentration of the second dopant in the topmostregion Ts of the fourth layer 107 may be in a range of 5×10¹⁷ cm⁻³ to1×10¹⁹ cm⁻³. Specifically, the concentration of the second dopant in thetopmost region Ts of the fourth layer 107 may be 1×10¹⁸ cm⁻³. When theconcentration of the second dopant in the topmost region Ts is 5×10¹⁷cm⁻³ or greater, a production amount of the second carrier may beincreased, so that the light-emitting efficiency of the active layer 21may be improved. When the concentration of the second dopant in thetopmost region Ts is smaller than or equal to 1×10¹⁹ cm⁻³, a productionamount of the second carrier may be increased, so that thelight-emitting efficiency of the active layer 210 may be improved.

In an embodiment, the concentration of the second dopant in the lowestregion Te of the fourth layer 107 may be zero. In a region adjacent tothe bottommost region Te of the fourth layer 107, for example, theconcentration may be 2×10¹⁷ cm⁻³.

When the fifth semiconductor layer 23 or the fifth semiconductor layer23 is omitted, the topmost region Ts of the fourth layer 107 may havethe same vertical level as that of the last well layer of the activelayer 21 adjacent to the second semiconductor layer 25. However, thepresent disclosure is not limited thereto.

When the fourth semiconductor layer 19 or the fourth semiconductor layer19 is omitted, the bottommost region Te of the fourth layer 107 may bepositioned above a bottom face of the active layer 21 adjacent to thesecond semiconductor layer 25. However, the present disclosure is notlimited thereto.

Following conditions may be satisfied so that the lowest point of thefourth layer 107, that is, the bottommost region Te of the fourth layer107 is positioned above the bottom face of the active layer 21.

In a first condition, the distance between the top region Ts and thebottom region of the fourth layer 107 may be smaller than the thicknessof the active layer 21. That is, the distance between the top region Tsand the bottom region of the fourth layer 107 may be 120 nm or smaller.

In a second condition, the arrangement density of the fourth layer 107may be in a range of 8×10¹⁷ cm⁻³ to 4×10¹⁸ cm⁻³. When the arrangementdensity of the fourth layer 107 is 8×10¹⁷ cm⁻³ or smaller, the depth ofthe fourth layer 107 is too small, such that the deep hole injectioneffect may not be properly implemented. When the arrangement density ofthe fourth layer 107 is 4×10¹⁸ cm⁻³ or greater, the fourth layer 107 mayvertically reaches the fourth semiconductor layer 19 located below theactive layer 21 or the third semiconductor layer 17 below thesemiconductor layer 19, such that the second semiconductor layer 25 andthe first semiconductor layer 15 in the fourth layer 107 are too closeto each other, thereby to generate an electrical short.

In a third condition, the size of the topmost region Ts of the fourthlayer 107 may be in a range of about 200 nm to about 400 nm. When thesize of the topmost region Ts of the fourth layer 107 is about 200 nm orsmaller, a deep hole injection effect may not be properly implemented.When the size of the topmost region Ts of the fourth layer 107 is about400 nm or greater, a substantial light-emitting area of the active layer21 may be reduced, so that the light-emitting efficiency may be reduced.

Therefore, when the above three conditions are satisfied, the lowestpoint of the fourth layer 107, that is, the bottommost region Te of thefourth layer 107 may be located above the bottom face of the at leastactive layer 21. In addition, in order that the bottommost region Te ofthe fourth layer 107 is positioned above the bottom face of the at leastactive layer 21, the second carrier profile as shown in FIG. 7 may bemet. That is, the concentration of the second dopant should be reducedin the fourth layer 107 having the same vertical level as that of theactive layer 21 and should be zero in the fifth layer 109 in the recess22 corresponding to the lower region of the active layer 21.

In one example, when the arrangement density of the fourth layer 107 isexcessive or the depth of the fourth layer 107 is larger, theconcentration of the second dopant in the second semiconductor layer 25disposed in the fourth layer 107 may be detected in the fourth layer 107having the same vertical level that of the third semiconductor layer 17via the active layer 21 and the fourth semiconductor layer 19, as shownin FIG. 8 . In this case, the lowest region Te of the fourth layer 107,that is, the lowest point may be located below the top face of the thirdsemiconductor layer 17. The larger depth of the fourth layer 107 may berelated to the increase in the size of the topmost region Ts of thefourth layer 107. That is, as the size of the topmost region Ts of thefourth layer 107 increases, the depth of the fourth layer 107 may belarger.

As described above, when the arrangement density of the fourth layer 107is 4×10¹⁸ cm⁻³ or greater, or when the size of the topmost region Ts ofthe fourth layer 107 is 400 nm or greater, the lowest point of thefourth layer 107 may be located below the top face of the thirdsemiconductor layer 17.

The lowest point of the fourth layer 107 may be located below the topface of the third semiconductor layer 17. Specifically, the lowest pointof the fourth layer 107 may coincide with the lowest point of the recess18 of the third semiconductor layer 17. The lowest point of the fourthlayer 107 may be located between the lowest point of the recess 18 ofthe third semiconductor layer 17 and the top face of the thirdsemiconductor layer 17.

The embodiment enables the recess 22 to be formed in the active layer 21due to the recess 18 formed in the third semiconductor layer 17, therebyrealizing the deep hole injection effect of the second semiconductorlayer 25 disposed in the fourth layer 107, thereby to improve the lightoutput and the operation voltage.

The embodiment may easily identify the shape of the recess 22 formed inthe active layer 21 based on the change in the concentration of thesecond dopant using the ion analysis device.

The embodiment continues the process of identifying the shape of therecess 22 formed in the active layer 21 using the ion analysis device,thereby providing the optimal recess structure, for example, a structurein which the lowest point of the recess of the active layer 21 islocated above the bottom face of the active layer 21. This may maximizethe effect of the deep hole injection, and the light extraction from theactive layer 21, thereby to improve the light efficiency, therebyimproving the light output and the operation voltage.

Horizontal Semiconductor Device

FIG. 11 shows a horizontal semiconductor device.

The horizontal semiconductor device may be manufactured by adding asubsequent process to a manufacturing process of the semiconductordevice according to the first embodiment shown in FIG. 1 .

Referring to FIG. 11 , when the semiconductor device according to thefirst embodiment shown in FIG. 1 is provided, mesa etching may beexecuted such that a partial region of the semiconductor structure maybe removed. That is, an edge region of each of the second semiconductorlayer 25, the fifth semiconductor layer 23, the active layer 21, thefourth semiconductor layer 19, the third semiconductor layer 17, and thefirst semiconductor layer 15 may be removed via the mesa etching. Anupper portion of the first semiconductor layer 15 may partially beremoved, and a lower portion thereof may not be removed.

Subsequently, a first electrode 27 may be disposed on the firstsemiconductor layer 15 which has been partially etched via the mesaetching. A second electrode 29 may be disposed on the secondsemiconductor layer 25. Each of the first electrode 27 and the secondelectrode 29 may be made of a metal material having excellentconductivity. Each of the first electrode 27 and the second electrode 29may include at least one layer.

A top face of the first electrode 27 may have a lower vertical levelthan that of the active layer 21 of the semiconductor structure. Thus,when light generated in the active layer 21 of the semiconductorstructure is emitted from the lateral face of the active layer 21, thelight may not be reflected from the first electrode 27.

Otherwise, the top face of the first electrode 27 may have a highervertical level than that of the active layer 21 of the semiconductorstructure. In this case, when light generated in the active layer 21 ofthe semiconductor structure is emitted from the lateral face of theactive layer 21, the light may be reflected from a lateral face of thefirst electrode 27.

Although not shown, a transparent electrode layer may be formed on thesecond semiconductor layer 25. The transparent electrode layer may beformed using a sputtering apparatus. However, the present disclosure isnot limited thereto.

When the transparent electrode layer is formed on the secondsemiconductor layer 25, the second electrode 29 may be disposed on thetransparent electrode layer.

The transparent electrode layer may be made of a transparent conductivematerial. The transparent electrode layer may be made of a materialhaving excellent ohmic characteristics with the second semiconductorlayer 25, and having excellent current spreading characteristics. Forexample, the transparent electrode layer may be made of at least oneselected from a group consisting of ITO, IZO (In—ZnO), GZO (Ga—ZnO), AZO(Al—ZnO), AGZO (Al—Ga ZnO), IGZO (In—Ga ZnO), IrO_(x), RuO_(x),RuO_(x)/ITO, Ni/IrO_(x)/Au, and Ni/IrO_(x)/Au/ITO. However, the presentdisclosure is not limited thereto.

After the transparent electrode layer is disposed on the secondsemiconductor layer 25, mesa etching may be performed. Alternatively,after the mesa etching is performed, the transparent electrode layer maybe disposed on the second semiconductor layer 25.

The transparent electrode layer may be disposed on the secondsemiconductor layer 25, and, then, the second electrode 29 may bedisposed on the transparent electrode layer Alternatively, thetransparent electrode layer may be disposed on the second semiconductorlayer 25, and then mesa etching may be performed, and then secondelectrode 29 may be disposed on the transparent electrode layer.

Although not shown, the horizontal semiconductor device shown in FIG. 11may be turned upside down, and may be adopted into a semiconductordevice package. In this case, the horizontal semiconductor device may beused as a flip-type semiconductor device. In this case, a reflectiveelectrode layer may be additionally disposed on the second semiconductorlayer 25. However, the present disclosure is not limited thereto.

Second Embodiment

FIG. 7 shows a second carrier profile when each layer has a recess. FIG.7 shows SIMS (Secondary Ion Mass Spectroscopy) data for detecting acomponent of each layer of a semiconductor device. The SIMS refers to amethod for irradiating primary ions to the semiconductor structure anddetecting secondary ions constituting the semiconductor structure asscattered by the primary ions and emitted. The SIMS may include TOF-SIMS(Time-of-Flight Secondary Ion Mass Spectrometry) and dynamic-SIMS.

The second embodiment relates to a component content and a dopingconcentration of each layer of a semiconductor device. The SIMS data maybe used to detect a secondary ion intensity and/or a dopingconcentration of each layer of the semiconductor device. SIMS may employTOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry). Thus, theSIMS data may refer to analysis data from the TOF-SIMS.

SIMS data may be obtained by irradiating the primary ions to a targetsurface, and counting the number of the secondary ions as emitted. Inthis connection, the primary ions may be selected from O₂ ⁺, Cs⁺, Bi⁺,etc. Acceleration voltage may be adjusted to a value within 20 keV to 30keV. Irradiation current may be adjusted to a value in a range of from0.1 pA to 5.0 pA. An irradiation area may be 20 nm×20 nm. However,conditions for measuring a sample are not limited thereto, and may varydepending on a component of the sample.

That is, the SIMS data may be used to detect the secondary ion intensityand/or the doping concentration included in each layer of thesemiconductor device. That is, when primary ions are irradiated to eachof the first conductive-type semiconductor layer, the active layer 21,and the second conductive-type semiconductor layer shown in FIG. 1 ,secondary ions may be emitted from the first conductive-typesemiconductor layer, the active layer 21, and the second conductive-typesemiconductor layer. Thus, the indium (In) ion intensity, the Siconcentration, and the Mg concentration included in each layer may bedetected based on the released secondary ions.

The SIMS data may include collection of secondary ion mass spectra whilegradually etching the semiconductor structure inwardly from a surface ofthe light emission structure (depth being zero).

Further, a result from the SIMS analysis may be interpreted as aspectrum related to the secondary ion intensity or the dopingconcentration of a material. In this connection, noise in a range of 0.9times to 1.1 times may occur in the analysis of the secondary ionintensity or the doping concentration. Therefore, the term “same as orequal to” may refer to inclusive noise of 0.9 to 1.1 times of onespecific secondary ion intensity or doping concentration.

Based on the SIMS data shown in FIG. 7 , a layer corresponding to eachof points {circle around (1)} to {circle around (7)}, and each ofsections S1 to S6 may be easily identified based on a relative intensityof secondary ions and/or a concentration of a dopant. In the secondaryion analysis, the secondary ion intensity may be expressed as a logscale. However, the present disclosure is not limited thereto. Thesecondary ion intensity may be expressed as a linear scale. Thesecondary ion intensity may mean an intensity of secondary ions that areemitted from the light emission structure after the primary ions areirradiated to the light emission structure. The secondary ions mayinclude at least one of In, Al, Ga, N, As, and P. In this embodiment,the relative intensity of the indium (In) ions is described. However,the present disclosure is not limited thereto. A relative intensity ofions of other materials may be referenced.

In the second embodiment, each of layers may be easily identified usingthe indium (In) ion intensity, and a concentration of each of the firstand second dopants as shown in a graph. For example, first to sixthpoints {circle around (1)} to {circle around (7)} may be defined usingthe indium (In) ion intensity, and the concentrations of the first andsecond dopants. The layers may be identified based on the first to sixthpoints {circle around (1)} to {circle around (7)} as defined asdescribed above. In a following description, the first dopant mayinclude the silicon (Si) and the second dopant may include magnesium(Mg).

In FIG. 7 , a region in which the indium (In) ion intensity is 0.3 to0.5 times larger than the highest indium (In) ion intensity within thesemiconductor structure may have a plurality of inflection points.Specifically, each of the plurality of inflection points may refer to aninflection point between a region where the indium (In) ion intensitydecreases in a direction toward the substrate, and a region where theindium (In) ion intensity increases in a direction toward a surface ofthe semiconductor structure. The inflection point may refer to a pointat which the indium (In) ion intensity may be minimum or maximum in thedirection to the surface or in the direction toward the substrate of thesemiconductor structure. Within the semiconductor structure, a peakpoint at which the indium (In) ion intensity may be maximum may bepresent. In a region in which the indium (In) ion intensity is 0.3 to0.5 times of the maximum indium (In) ion intensity, a point at which theindium (In) ion intensity is minimum may be present.

A point at which the indium (In) ion intensity has the same the indium(In) ion intensity as that of the lowest peak among the plurality ofinflection points and which is closest to the surface may be defined asthe first point {circle around (1)}. In addition, each of the secondpoint {circle around (2)}, the third point {circle around (3)}, and thefourth point {circle around (4)} may have the same indium (In) ionintensity as the indium (In) ion intensity as the lowest peak. In thisconnection, the second point {circle around (2)} may be closest to thesubstrate, then the third point {circle around (3)} may be adjacent tothe second point {circle around (2)} in the direction toward thesurface, and the fourth point {circle around (4)} may be adjacent to thethird point {circle around (3)} in the direction toward the surface.

A region between the first point {circle around (1)}, and second point{circle around (2)} may be defined as the first section S1. For example,the first section may be the active layer that generates light. A regionbetween the second point {circle around (2)} and third point {circlearound (3)} may be defined as the second section S2. For example, thesecond section may be a carrier injection layer that facilitates carrierinjection. A region between the third point {circle around (3)} and thefourth point {circle around (4)} may be defined as the third section S3.For example, the third section may be a superlattice layer, a currentspreading layer, or a stress relaxation layer. In this connection, thecarrier may be an electron.

In FIG. 7 , the fifth point {circle around (5)} at which theconcentration of the first dopant is the same as the highest firstdopant concentration in a region with the concentration of the firstdopant is 0.1 times to 0.2 times of the first dopant concentration atthe highest peak. The fifth point {circle around (5)} may be closest tothe substrate.

A region between the fourth point {circle around (4)} and the fifthpoint {circle around (5)} may be defined as the fourth section S4. Forexample, the fourth section may be a middle temperature (MT) layer. Asdescribed above, the middle temperature may be a temperature for growingthe middle temperature layer. The growth rate in the vertical direction,and the horizontal direction of the middle temperature layer may becontrolled by adjusting the temperature, adjusting the indium (In)content, and adjusting the thickness of each sub-semiconductor layer inthe middle temperature layer, so that a plurality of recesses may beformed therein. For example, the recess may have a V-pit shape. When themiddle temperature layer has the recess, each of a superlattice layer, acarrier injection layer, and an active layer may have a recesscorresponding to the recess in the MT layer.

In one example, a curve of the concentration of the second dopant mayhave a plurality of inflection points V11, V12, and V13. The pluralityof inflection points V11, V12, and V13 may be arranged between thesurface of the semiconductor structure and the first point {circlearound (1)}. The second inflection point V12 may be lower than the firstinflection point V11, and the third inflection point V13 may be lowerthan the first, and second inflection points V11, and V12. In this case,the first inflection point V11 at which the concentration of the seconddopant is the highest, and which is closest to the first point {circlearound (1)} in the direction toward the surface of the semiconductorstructure may be defined as the sixth point {circle around (6)}. In thiscase, a region between the first point {circle around (1)} and sixthpoint {circle around (6)} may be defined as the fifth section S5. Forexample, the fifth section may be a carrier injection layer. In thisconnection, the carrier may be an electron. The second inflection pointV12 at which the concentration of the second dopant is lower than thatof the first inflection point V11, and is higher than that of the thirdinflection point V13, and which is adjacent to the sixth point {circlearound (6)} in the direction toward the surface of the semiconductorstructure may be defined as the seventh point {circle around (7)}. Aregion between sixth point {circle around (6)} and seventh point {circlearound (7)} may be defined as the sixth section S6. For example, thesixth section may be a carrier injection layer. In this connection, thecarrier may be a hole.

The first to seventh points {circle around (1)} to {circle around (7)}may have the designated and different orders.

In one example, a position of the third inflection point 13, and aposition of the first point {circle around (1)} may be the same as eachother. That is, the third inflection point 13, and the first point{circle around (1)} may be located on the same plane.

Hereinafter, the points {circle around (1)} to {circle around (7)}, andthe sections S1 to S6 between the points {circle around (1)} to {circlearound (7)} and will be described in detail.

A plurality of peaks P11 and P12, and valleys P21 and P22 may bearranged in a region between the first point {circle around (1)} and thesecond point {circle around (2)}. The first valleys P21 may bealternately arranged with the first peaks P11. The second valleys P22may be alternately arranged with the second peaks P12. In addition, theplurality of second peaks P12, and the plurality of second valleys P22may be alternately arranged with each other. The indium (In) ionintensity of the second peak P12 may be lower than the indium (In) ionintensity of the first peak P11. The indium (In) ion intensity of thesecond valley P22 may be lower than the indium (In) ion intensity of thefirst valley P21. The third valley P23 may have the indium (In) ionintensity lower than that of each of the first and second valleys P21and P22. A difference D11 between the indium (In) ion intensity of thefirst peak P11, and the indium (In) ion intensity of the second peak P12may be smaller than a difference D21 between the indium (In) ionintensity of the first valley P21, and the indium (In) ion intensity ofthe second valley P22. The difference D11 between the indium (In) ionintensity of the first peak P11, and the indium (In) ion intensity ofthe second peak P12 may be the same as a difference D21 between theindium (In) ion intensity of the first valley P21, and the indium (In)ion intensity of the second valley P22.

In the region between the first point {circle around (1)} and the secondpoint {circle around (2)}, the highest peak of the indium (In) ionintensity may be located. The highest peak may be one of the pluralityof first peaks P11. The second peak P11 may have the indium (In) ionintensity which may be 0.93 times to 0.95 times of that of the highestpeak. The first valley P21 may have the indium (In) ion intensity whichmay be 0.9 to 0.93 times of that of the highest peak. The second valleyP22 may have the indium (In) ion intensity which may be 0.3 to 0.5 timesof that of the highest peak. The region between the first point {circlearound (1)}, and the second point {circle around (2)} may be the activelayer. Further, the active layer may correspond to the active layer ofthe first embodiment as described above, but is not necessarily limitedthereto. Among the plurality of peaks P11 and P12, and valleys P21 andP22 in terms of the indium (In) ion intensity, the highest peak maycorrespond to the well layer. When a barrier layer having the indium(In) ion intensity which is 0.3 to 0.5 times of the indium (In) ionintensity of the peak P11 is present, the light-emitting efficiency ofthe semiconductor device may be improved.

A peak of the concentration of the first dopant may be present in theregion between the second point {circle around (2)} and the third point{circle around (3)}. The highest concentration of the first dopant inthis region may be 0.2 to 0.35 times of that of the highest peak of thefirst dopant concentration in an entirety of the semiconductorstructure. In the region between the second point {circle around (2)}and the third point {circle around (3)}, a valley in terms of the indiumion intensity may be located. A difference D22 between the indium (In)ion intensity of the located valley, and the indium (In) ion intensityof the valley P22 of the first section S1 may be greater than thedifference D21 between the indium (In) ion intensity of the valley P21of the first section S1, and the indium (In) ion intensity of the valleyP22. For example, the difference D22 between the indium (In) ionintensity of the located valley, and the indium (In) ion intensity ofthe valley P22 of the first section S1 may be 1 to 5 times larger thanthe difference D21 between the indium (In) ion intensity of the valleyP21 of the first section S1, and the indium (In) ion intensity of thevalley P22. However, the present disclosure is not limited thereto.

In the region between the third point {circle around (3)}, and thefourth point {circle around (4)}, at least one peak in terms of theindium ion intensity may be arranged. The at least one peak in terms ofthe indium (In) ion intensity may have the indium (In) ion intensitywhich may be 0.7 to 0.85 times of that of the highest peak.

In the region between the fourth point {circle around (4)} and the fifthpoint {circle around (5)}, a plurality of peaks, and valleys in terms ofthe indium (In) ion intensity may be arranged. The peak may have theindium (In) ion intensity which may be 0.5 to 0.7 times of that of thehighest peak. The valley may be the lowest point between the pluralityof peaks in terms of the indium (In) ion intensity.

The sixth point {circle around (6)} may have the first inflection pointV11 in terms of the concentration of the second dopant. The seventhpoint {circle around (7)} may have the second inflection point V12 interms of the concentration of the second dopant. The first point {circlearound (1)} may have the third inflection point V13 in terms of thesecond dopant concentration. That is, the third inflection point V13 maybe located at the same point as the first point {circle around (1)}. Inaddition, a fourth inflection point V14 may be present in a specificportion of the region between the first point {circle around (1)} andthe second point {circle around (2)}.

The concentration of the second dopant at the first inflection point V11may be highest. The second inflection point V12 may be lower than thefirst inflection point V11. The third inflection point V13 may be lowerthan the second inflection point V12. The fourth inflection point V14may be lower than the third inflection point V13.

The concentration of the second dopant may decrease in a direction fromthe first inflection point V11 to the second inflection point V12 in thedirection toward the surface of the semiconductor structure. Thegradient at which the concentration of the second dopant decreasesbetween the first inflection point V11, and the second inflection pointV12 may be defined as a first gradient G11. The concentration of thesecond dopant may decrease in a direction from the first inflectionpoint V11 to the third inflection point V13 toward the substrate 11. Thegradient at which the concentration of the second dopant decreasesbetween the first inflection point V11, and the third inflection pointV13 may be defined as a second gradient G12. The concentration of thesecond dopant may decrease in a direction from the third inflectionpoint V13 to the fourth inflection point V14 toward the substrate 11.The gradient at which the concentration of the second dopant decreasesbetween the third inflection point V13, and the fourth inflection pointV14 may be defined as a third gradient G13.

As shown in FIG. 7 , the first inflection point V11 has a peak, and thesecond inflection point V12 may have a valley. The third inflectionpoint V13 may be a point where different gradients, for example, thesecond gradient G12, and the third gradient G13 meet each other. Thefourth inflection point V14 may be the endpoint of the concentration ofthe second dopant shown in FIG. 7 . That is, the concentration of thesecond dopant is zero in a region between the fourth inflection pointV14 and the substrate 11. This may mean that the second dopant is notdoped into the region between the substrate 11 and the fourth inflectionpoint V14. The growth rate in the vertical and horizontal directions ofthe region between the fourth point {circle around (4)} and the fifthpoint {circle around (5)}, that is, the fourth section S4 may becontrolled via the temperature adjustment during the growth thereof, theadjustment of the indium (in) content therein, and a spacing between thepeak and the valley in terms of the concentration of the second dopant.Thus, the plurality of recesses may be formed. For example, the recessmay have a V-pit shape. Due to the recess of the fourth section S4, eachof the third section S3, the second section S2, and the first section S1may have a recess. In this case, the second dopant may be doped into thefifth section S5, and sixth section S6 and the recesses thereof.Therefore, the size or the depth of the recess may be easily identifiedbased on a length between the third inflection point V13, and the fourthinflection point V14 in terms of the concentration of the second dopantor the gradient between the third inflection point V13, and the fourthinflection point V14 in terms of the concentration of the second dopant.

The second gradient G12 may be larger than the first gradient G11. Thethird gradient G13 may be smaller than the second gradient G12. Thethird gradient G13 may be smaller than the first gradient G11. However,the present disclosure is not limited thereto. The first to thirdgradient G11, G12, and G13 may vary depending on the concentration ofthe second dopant. In particular, the third gradient G13 may varydepending on the shape of the recess 22 as described above. In addition,the position of the fourth inflection point V14 may also vary dependingon the shape of the recess 22. This will be described later.

Therefore, the concentration of the second dopant may be increased fromthe second inflection point V12 at the first gradient G11 to reach thefirst inflection point V11 and may be decreased from first inflectionpoint V11 at the second gradient G12 to reach the third inflection pointV13, and may be decreased from the third inflection point V13 at thethird gradient G13 to reach the fourth inflection point V14. After theconcentration reaches the fourth inflection point V14, the concentrationof the second dopant is zero. That is, the concentration of the seconddopant is zero in a region between the substrate 11 and the fourthinflection point V14.

In one example, the first section S1 may include a first sub-sectionS11, and a second sub-section S12. For example, the first sub-sectionS11 may be defined as a region between the third inflection point V13,and the fourth inflection point V14 in terms of the concentration of thesecond dopant. The second sub-section S12 may be defined as a regionbetween the fourth inflection point V14, and the second point (in termsof the concentration of the second dopant.

In the first sub-section S11, the concentration of the second dopant maydecrease in a direction from the third inflection point V13 to thefourth inflection point V14 at the third gradient G13. The firstsub-section S11 may include a plurality of first peaks P11 and aplurality of first valleys P21 which are alternately arranged with eachother. Further, some second peaks and/or second valleys among theplurality of the second peaks P12 and plurality of second valleys P22alternately arranged with each other may be positioned in the firstsub-section S11. For example, the first sub-section S11 may include atleast one second valley P22 or second peak P12 adjacent to the lastfirst peak P11, among the plurality of second peaks P12 and theplurality of second valley P22.

Thus, the fourth layer 107 may be identified based on the firstsub-section S11, in that in the first sub-section S11, the concentrationof the second dopant may decrease in a direction from the thirdinflection point V13 to the fourth inflection point V14 at the thirdgradient G13; and the first sub-section S11 includes the plurality offirst peaks P11 and the plurality of first valleys P21 which arealternately arranged with each other, and some second peaks and/orsecond valleys of the plurality of second peaks P12 and the plurality ofsecond valleys P22.

The third inflection point V13 among the third inflection point V13 andfourth inflection point V14 defining the first sub-section S11 maycorrespond to the topmost region Ts of the fourth layer 107, and thefourth inflection point V14 may correspond to the bottommost region Teof the fourth layer 107. Therefore, in the fourth layer 107, theconcentration of the second dopant is highest in the topmost region Tsof the fourth layer 107, and the concentration of the second dopant islowest or zero in the bottommost region Te of the fourth layer 107. Itmay be seen that the concentration of the second dopant decreases in adirection from the topmost region Ts of the fourth layer 107 to thebottommost region Te thereof. From this finding, it may be seen that thesize of the recess 22 decreases as the recess 22 extends in a directionfrom the topmost region Ts to the bottommost region Te. As a result,because the size of the recess 22 decreases in a direction from the topregion Ts toward the bottom region Te, an amount of the second dopantsdetected in the topmost region Ts where the size of the recess 22 islarge may be larger, while an amount of the second dopants detected inthe bottommost region Te where the size of the recess 22 is small may besmaller. Accordingly, a profile that the concentration of the seconddopant decreases from the third inflection point V13 to the fourthinflection point V14 at the third gradient G13 may be obtained. Theconcentration of the second dopant may be zero in the lowest region Teof the fourth layer 107. However, the recess 22 in the bottommost regionTe of the fourth layer 107 may have a predetermined size. As shown inFIG. 1 , the recess 22 may pass through the active layer 21, the fourthsemiconductor layer 19, and the third semiconductor layer 17, andterminate at or above the bottom of third semiconductor layer 17. Thatis, the size of the recess 22 at or above the bottom of the thirdsemiconductor layer 17 may be zero.

As described above, the recess 22 may pass through the active layer 21,the fourth semiconductor layer 19, and the third semiconductor layer 17,and terminates at or above the bottom of the third semiconductor layer17. Thus, the distribution of the second dopant in the recess 22 mayvary depending on the size and the depth of the recess 22 in the topmostregion Ts. Accordingly, a position of the fourth inflection point V14from which the concentration of the second dopant is zero may vary. Forexample, as shown in FIG. 7 , the fourth inflection point V14 may belocated in the third semiconductor layer 17.

Therefore, the location of the fourth inflection point V14 may beidentified using the SIMS data as shown in FIG. 7 . Based on theidentification result, the size or the depth of the recess 22 may becontrolled during the deposition process such that the position of thefourth inflection point V14 is present in a region including some peaksand/or valleys among the plurality of the second peaks P12, and theplurality of second valleys P22 which are alternately arranged with eachother, as shown in FIG. 7 . In this way, an optimal semiconductor devicethat may improve light output, and operation voltage may be realized.

In addition, identifying a position of the fourth inflection point V14based on the SIMS data as shown in FIG. 7 may allow easily evaluatingthe quality of the semiconductor device based on the identified locationof the fourth inflection point V14.

In one example, the concentration of the second dopant is zero in thesecond sub-section S12. Further, the second sub-section S12 may includeremaining second peaks P12 and the second valleys P22 which are notincluded in the first sub-section S11, among the plurality of secondpeaks P12, and the plurality of second valleys P22 alternately arrangedwith each other.

Thus, the fifth layer 109 may be identified based on the secondsub-section S12, in that in the second sub-section S12, theconcentration of the second dopant is zero, and the second sub-sectionS12 includes the remaining second peaks P12 and the second valleys P22which are not included in the first sub-section S11, among the pluralityof second peaks P12, and the plurality of second valleys P22 alternatelyarranged with each other.

In FIG. 7 , the region between the fourth inflection point V14 and thesecond point {circle around (2)} may be defined as the fifth layer 109.However, the recess 22 may pass through not only the active layer 21 butalso the fourth semiconductor layer 19, and the third semiconductorlayer 17. Thus, the fourth inflection point V14 may be located in anyone of the fourth semiconductor layer 19, and the third semiconductorlayer 17. However, the present disclosure is not limited thereto. It isclear that the concentration of the second dopant will be zero in thefifth layer 109 identified based on the second sub-section S12 as theregion between the fourth inflection point V14 and the second point{circle around (2)} even when the position of the fourth inflectionpoint V14 changes. Therefore, the fifth layer 109 may be an undopedsemiconductor layer that does not include the dopant.

In the fifth section S5, the concentration of the second dopant may havethe second gradient G12. That is, the concentration of the second dopantmay decrease from the first inflection point V11 to the third inflectionpoint V13 toward the substrate 11 at the second gradient G12.

As such, the first layer 101 may be identified based on the fifthsection S5 having the second gradient G12 at which the second dopantconcentration decreases from the first inflection point V11 to the thirdinflection point V13. The first layer 101 may correspond to the fifthsection S5. However, the present disclosure is not limited thereto.

In the sixth section S6, the concentration of the second dopant may havethe first gradient G11. That is, the concentration of the second dopantmay decrease from the first inflection point V11 to the secondinflection point V12 along the direction toward the surface of thesemiconductor structure at the first gradient G11.

As such, the second layer 103 may be identified based on the sixthsection S6 in which the concentration of the second dopant decreasesfrom the first inflection point V11 to the second inflection point V12at the first gradient G11. The second layer 103 may correspond to thesixth section S6. However, the present disclosure is not limitedthereto.

As described above, the first to seventh points {circle around (1)} to{circle around (7)}, and the first to fourth inflection points V11, V12,V13, and V14 may be defined based on the data on the concentration ofthe second dopant and/or the indium (In) ion intensity as shown in FIG.7 . Thus, the first to sixth section S1 to S6 may be easily identifiedbased on the first to seventh points {circle around (1)} to {circlearound (7)}. Thus the first to fifth layers 101, 103, 105, 107, and 109may be easily identified based on the first to fourth inflection pointsV11, V12, V13, and V14. In particular, the shape of the recess 22 may beestimated based on the profile of the second dopant in the fourth layer107 disposed in the recess 22. Controlling the shape of the recess 22such that a last point from which the concentration of the second dopantis zero, that is, the fourth point {circle around (4)} is located in theactive layer 21 may allow implementing an optimal semiconductor devicecapable of improving the light output, and the operation voltage.

In addition, identifying a position of the fourth inflection point V14using the SIMS data as shown in FIG. 7 may allow the quality of thecorresponding semiconductor device to be easily evaluated.

As described above, according to the analysis method of each layer usingthe graph according to the second embodiment, the plurality of pointsmay be defined based on the indium (In) ion intensity, and the firstdopant concentration, and the second dopant concentration. Then, thedefined points may be used to easily grasp the shape, the size, and/orthe depth of the recess as well as each of the plurality of layers.

Semiconductor Device Package

FIG. 12 shows a semiconductor device package according to an embodiment.

As shown in FIG. 12 , a semiconductor device package according to anembodiment may include a body 311 having a cavity 315, a first leadframe 321 and a second lead frame 323 disposed within the body 311, thesemiconductor device 100, wires 331, and a molding member 341.

The body 311 may include a conductive material or an insulatingmaterial. The body 311 may be made of at least one of resin material,silicon material, metal material, PSG (photo sensitive glass), sapphire(Al₂O₃), and a printed circuit board PCB. The resin material may be PPA(polyphthalamide) or epoxy.

The body 311 has the cavity 315 having an open top. The cavity 315 mayinclude a cup structure or a recess structure that is concave from a topface of the body 311. However, the present disclosure is not limitedthereto.

The first lead frame 321 is placed in a first region of a bottom regionof the cavity 315. The second lead frame 323 is disposed in a secondregion of the bottom region of the cavity 315. The first lead frame 321and the second lead frame 323 may be spaced apart from each other withinthe cavity 315.

Each of the first and second lead frames 321 and 323 may be made of atleast one selected from metal materials, for example, titanium (Ti),copper (Cu), nickel (Ni), gold (Au), chromium (Cr), tantalum (Ta),platinum (Pt), tin (Sn), silver (Ag), and phosphorus (P). Each of thefirst and second lead frames 321 and 323 may be formed of a single metallayer or a metal multi-layer stack.

The semiconductor device 100 may be disposed on at least one of thefirst and second lead frames 321 and 223. The semiconductor device 100may be disposed, for example, on the first lead frame 321 and the wire331 may be connected to the first and second lead frames 321 and 223.

The semiconductor device 100 may emit light beams in at least twowavelength regions. The semiconductor device 100 may include a groupIII-V compound semiconductor or a group II-VI compound semiconductor.The semiconductor device 100 may employ the technical features of FIG. 1to FIG. 9 .

The molding member 341 may be disposed in the cavity 315 of the body311. The molding member 341 may include a translucent resin layer suchas silicon or epoxy. The molding member 341 may be formed in a singlelayer or multiple layers.

The molding member 341 may include a phosphor for changing a wavelengthof light emitted from the semiconductor device 100 or may not includethe phosphor.

For example, when the semiconductor device in which blue light and greenlight are generated is adopted in the semiconductor device packageaccording to the embodiment, the molding member 341 may include, forexample, a red phosphor. Therefore, white light may be rendered via amixture of the blue light and green light generated from thesemiconductor device, and the red light wavelength-converted by the redphosphor included in the molding member.

For example, when the semiconductor device according to each of thethird to fifth embodiments, in which all of blue light, green light, andred light are generated, is adopted in the semiconductor device packageaccording to embodiment, the molding member 341 may not include the redphosphor. Even in this case, the molding member may include a phosphorthat generates color light other than the red light, when necessary.However, the present disclosure is not limited thereto.

A surface of the molding member 341 may be formed into a flat shape, aconcave shape, a convex shape, etc. However, the present disclosure isnot limited thereto.

A lens (not shown) may be further formed on a top face of the body 311.The lens may include a concave or/and convex lens structure and maycontrol the light distribution of the light emitted from thesemiconductor device 100.

A protective element (not shown) may be disposed in the semiconductordevice package. The protection element may be implemented as athyristor, a Zener diode, or TVS (transient voltage suppression)element.

In one example, the semiconductor device package according to theembodiment may be applied to a light-source device.

Further, the light-source device may include a display, an illuminationdevice, a head lamp, etc. according to an industrial field.

An example of a light-source device may include a display. The displaymay include a bottom cover, a reflective sheet disposed on the bottomcover, a light-emitting module including a light-emitting element, alight-guide sheet disposed in front of the reflective sheet, and guidingthe light emitted from the light-emitting module in a front direction,an optical sheet including prism sheets disposed in front of thelight-guide sheet, a display panel disposed in front of the opticalsheet, an image signal output circuit connected to the display panel forsupplying an image signal to the display panel, and a color filterdisposed in front of the display panel. In this connection, the bottomcover, the reflective sheet, the light-emitting module, the light-guidesheet, and the optical sheet may form a backlight unit. Further, thedisplay does not include the color filter. Rather, the display may havea structure in which light-emitting devices for emitting red, green, andblue light beams are disposed, respectively.

Another example of the light-source device may include the head lamp.The head lamp may include a light-emitting module including asemiconductor device package disposed on a substrate, a reflector forreflecting light irradiated from the light-emitting module in apredetermined direction, for example, in a front direction, a lens thatrefracts light reflected from the reflector in a front direction, and ashade for blocking or reflecting a portion of the light reflected fromthe reflector toward the lens to form a light-distribution patterndesired by a designer desires.

Another example of the light-source device may include the illuminationdevice. The illumination device may include a cover, a light-sourcemodule, a radiator, a power supply, an inner casing, and a socket.Further, the light-source device according to an embodiment may furtherinclude at least one of a member and a holder. The light-source modulemay include the semiconductor device package according to theembodiment.

Features, structures, effects, etc. as described above in theembodiments are included in at least one embodiment, and is notnecessarily limited to one embodiment. Furthermore, the features,structures, effects, etc. exemplified in the embodiments may be combinedwith each other or modified in other embodiments by a person havingordinary knowledge in the field to which the embodiments belong.Therefore, contents related to such combinations, and modificationsshould be interpreted as being included in the range of the disclosure.

The embodiment has been mainly described, but this is merely an example,and does not limit the present disclosure. Those of ordinary skill inthe field to which the embodiment belongs will find that variousmodifications, and applications as not exemplified above are possiblewithin a range that does not depart from the essential characteristicsof the present disclosure. For example, each component specificallyshown in the embodiment may be modified. In addition, variations relatedto the modifications and applications should be interpreted as beingincluded in the range of the disclosure set in the attached claims.

The embodiments may be applied to a semiconductor device, and to a fieldrelated thereto.

What is claimed is:
 1. A semiconductor device comprising: a firstconductive-type semiconductor layer; a second conductive-typesemiconductor layer on the first conductive-type semiconductor layer;and an active layer disposed between the first conductive-typesemiconductor layer and the second conductive-type semiconductor layer;wherein when primary ions are irradiated to the first conductive-typesemiconductor layer, the active layer, and the second conductive-typesemiconductor layer, secondary ions are emitted from the firstconductive-type semiconductor layer, the active layer, and the secondconductive-type semiconductor layer, wherein an indium (In) ionintensity, a silicon (Si) concentration, and a magnesium (Mg)concentration of the first conductive-type semiconductor layer, theactive layer, and the second conductive-type semiconductor layer aredetected based on the emitted secondary ions, wherein the semiconductordevice has a plurality of inflection points of the indium (In) ionintensity, wherein the indium (In) ion intensities at the plurality ofinflection points are 0.3 to 0.5 times of a highest indium (In) ionintensity in a vertical entire region of the semiconductor device,wherein the semiconductor device has: a first point having the sameindium (In) ion intensity as a lowest indium (In) ion intensity amongthe indium (In) ion intensities at the plurality of inflection points; asecond point having the same indium (In) ion intensity as the firstpoint, wherein the second point is adjacent to the first point, and thefirst point is closer to a first vertical end of the semiconductordevice than the second point; a first inflection point of the Mgconcentration located at the same point as the first point; a secondinflection point of the Mg concentration adjacent to the firstinflection point in a direction toward the first vertical end of thesemiconductor device, wherein the second inflection point has the Mgconcentration higher than the Mg concentration of the first inflectionpoint; and a third inflection point of the Mg concentration adjacent tothe second inflection point in the direction toward the first verticalend of the semiconductor device, wherein the third inflection point hasthe Mg concentration higher than the Mg concentration of the firstinflection point, and lower than the Mg concentration of the secondinflection point, wherein the active layer corresponds to a regionbetween the first point and the second point, wherein the secondconductive-type semiconductor layer includes a firstsecond-conductive-type semiconductor layer and a secondsecond-conductive-type semiconductor layer, wherein the firstsecond-conductive-type semiconductor layer corresponds to a regionbetween the first point and the second inflection point, and the secondsecond-conductive-type semiconductor layer corresponds to a regionbetween the second inflection point and the third inflection point,wherein the Mg concentration in the first second-conductive-typesemiconductor layer increases in a direction toward the first verticalend of the semiconductor device, wherein the Mg concentration in thesecond second-conductive-type semiconductor layer decreases in adirection toward the first vertical end of the semiconductor device,wherein in a region between the first point and the second point, theindium (In) ion intensity includes a plurality of first peaks andvalleys alternately arranged with each other and a plurality of secondpeaks and valleys alternately arranged with each other, wherein theindium (In) ion intensity of the plurality of second peaks and valleysis lower than the indium (In) ion intensity of the plurality of firstpeaks and valleys, and wherein a difference between the indium (In) ionintensity of a highest first peak and the indium (In) ion intensity of ahighest second peak is smaller than a difference between the indium (In)ion intensity of a lowest first valley and the indium (In) ion intensityof a lowest second valley.
 2. The semiconductor device of claim 1,wherein the semiconductor device further has: a fourth inflection pointadjacent to the first inflection point in a direction toward a secondvertical end of the semiconductor device, wherein the fourth inflectionpoint has the Mg concentration lower than the Mg concentration of thefirst inflection point, and wherein the first and second vertical endsare opposite to each other, wherein the active layer includes a firstlayer and a second layer, wherein the first layer corresponds to aregion between the first inflection point and the fourth inflectionpoint, wherein the second layer corresponds to a region between thefourth inflection point and the second point.
 3. The semiconductordevice of claim 2, wherein the Mg concentration in the first layerdecreases in the direction toward the second vertical end of thesemiconductor device.
 4. The semiconductor device of claim 2, whereinthe Mg is absent in the second layer.
 5. The semiconductor device ofclaim 2, wherein a first gradient of the Mg concentration in the firstsecond-conductive-type semiconductor layer is greater than a secondgradient of the Mg concentration in the second second-conductive-typesemiconductor layer.
 6. The semiconductor device of claim 5, wherein athird gradient of the Mg concentration in the first layer is smallerthan the first gradient of the Mg concentration in the firstsecond-conductive-type semiconductor layer.
 7. The semiconductor deviceof claim 6, wherein at the first inflection point, the first gradient ofthe Mg concentration meets the third gradient of the Mg concentration,and wherein at the second inflection point, the second gradient of theMg concentration meets the first gradient of the Mg concentration. 8.The semiconductor device of claim 1, further comprising: a third pointpresent in a partial region where the Si concentration is lower than ahighest Si concentration in the vertical entire region of thesemiconductor device, wherein the third point has a highest Siconcentration in the partial region and the same indium (In) ionintensity as the first and second points, wherein the third point isadjacent to the second point, and the second point is closer to thefirst vertical end of the semiconductor device than the third point, andwherein the first conductive-type semiconductor layer corresponds to aregion between the second point and the third point.
 9. Thesemiconductor device of claim 8, further comprising: a fourth pointhaving the same indium (In) ion intensity as the first, second and thirdpoints, wherein the fourth point is adjacent to the third point, and thefourth point is closer to a second vertical end of the semiconductordevice than the third point, wherein the first and second vertical endsare opposite to each other; and a fifth point having an indium (In) ionintensity lower than that of the first, second, third, and fourthpoints, wherein the fifth point is adjacent to the fourth point, and thefifth point is closer to the second vertical end of the semiconductordevice than the fourth point.
 10. The semiconductor device of claim 9,wherein the first conductive-type semiconductor layer includes a firstfirst-conductive-type semiconductor layer, a secondfirst-conductive-type semiconductor layer, and a thirdfirst-conductive-type semiconductor layer, wherein the firstfirst-conductive-type semiconductor layer corresponds to a regionbetween the second point and the fourth point, and has a peak of the Siconcentration, and a valley of the indium (In) ion intensity, whereinthe second first-conductive-type semiconductor layer corresponds to aregion between the fourth point and the fifth point, and wherein thethird first-conductive-type semiconductor layer corresponds to a regionbetween the fifth point and the second vertical end.